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UC-NRLF 


Us 

1912 


UHiTI  D  STATES  DEPARTRiOCT  OF  &Git!CULTk*B£ 

FOREST  SERVI'C;:? 
HENRY  S.  GRAVES,  FORESTEK 


INSTRUOTJONS  FOR  MAKING 

FOREST  SURVEYS 

AND  !V!APS 


1912 


LO 
O 

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AGRIC.  OEPTt 


Issued  April  11,  1912. 

U.  S.  DEPARTMENT   OF  AGRICULTURE, 

FOREST  SERVICE. 

HENRY  S.  GRAVES,  FORESTER. 


INSTRUCTIONS  FOR  MAKING 

FOREST   SURVEYS 

AND  MAPS. 


REVISED   DECEMBER  15,  1911. 


1912. 


PREPARED    IN   THE    OFFICE    OF   GEOGRAPHY. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE, 
1912. 


CONTENTS. 


Page. 

Elements  of  surveying  and  mapping 5 

Instruments  used 7 

Forest  Service  standard  compass 9 

The  pocket  compass 14 

Magnetic  needle 16 

Variation 16 

Observing  Polaris 18 

Observing  the  sun  at  noon 21 

Plane  table 23 

Aneroid  barometer 28 

Hypsometer ,. 29 

Details  of  surveying 31 

Measurements 31 

Concerning  accuracy 31 

Traverse 32 

Blazes  and  marks  on  trees 41 

Field  notes,  etc 44 

Elevation  from  vertical  angles 50 

Tying  in 51 

Ranger  station  surveys. 52 

Forest  homestead  surveys 58 

Trail  surveys 59 

Platting  the  surveys 64 

Map  making  in  the  field 64 

The  Forest  Atlas : 66 

Conventional  signs 69 

Lettering , 70 

Color  prescriptions 73 

Forest  Atlas  crayons 75 

Mounting  maps  on  muslin 76 

3 

293305 


4  CONTENTS    AND   ILLUSTRATIONS. 

Page. 

Determination  of  areas  by  planimeter 78 

Land  Office  surveys 81 

Resurveys 83 

Cancellation  of  misleading  marks 83 

Physiographic  features 85 


ILLUSTRATIONS. 


Page. 

FIG.  1.  Forest  Service  standard  compass 10 

2.  Standard  pocket  compass 15 

3.  Lines  of   equal   magnetic   variation   in   the   United 

States 17 

4.  Positions  of  Polaris,  Big  Dipper,  and  Cassiopeia 18 

5.  Plane-table  method  in  which  the  table  is  set  up  at  all 

the  stations 24 

6.  Plane-table  method  in  which  the  table  is  set  up  at 

two  stations  and  the  remaining  three  are  located 

by  intersections 25 

7.  Plane-table  method  of  locating  points  on  both  sides  of 

a  base  line  which  are  to  be  occupied  later  and  the 

survey  extended 26 

8.  Plane-table  method  of  finding  location  from  three 

points 27 

9.  Method  of  sighting  with  standard  hypsometer 29 

10.  Areas  of  a  section  containing  a  compass  error  of  0.25°.  32 

11.  Ranger-station  plat 55 

12.  Standard  planimeter 78 

13.  Rectangular  system  of  Land  Office  surveys 81 

14.  Names  of  physiographic  features 85 


INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS  AND  MAPS. 


ELEMENTS   OF   SURVEYING  AND   MAPPING. 

These  simple  instructions  are  issued  to  members  of  the 
Forest  Service  in  order  that  forest  surveys  and  maps 
may  be  as  nearly  uniform  as  practicable.  They  do  not 
include  directions  for  the  use  of  instruments  of  great 
precision,  and  the  tables  are  prepared  only  to  such 
accuracy  as  is  attained  in  careful  timber  cruising  or  in 
surveying  with  the  magnetic  compass.  This  is  J°  or  15' 
of  arc.1 

Forest  surveys  are  made  for  two  purposes — to  locate 
and  mark  lines  or  boundaries  upon  the  ground,  or  to 
furnish  data  for  the  preparation  of  maps. 

The  correctness  of  a  survey  depends  upon  the  excel- 
lence of  the  instruments  in  use  and  the  skill  of  the  sur- 
veyor and  his  party.  A  skillful  surveyor  can  do  better 
work  with  poor  instruments  than  an  unskilled  or  care- 
less one  with  the  best  instruments.  Small  instrumental 

i  The  "diurnal"  or  daily  change  of  a  magnetic  needle,  which  is  one  of  the  variations 
for  which  allowance  is  made  in  precise  surveying,  amounts  to  10'  or  15',  and  the  influ- 
ence of  magnetic  storms  upon  the  needle  is  frequently  unsuspected  at  the  time  a  survey 
is  made. 

Clinometers  and  clinometer  compasses,  by  which  the  degree  of  a  slope  or  a  vertical 
angle  may  be  measured,  are  generally  read  only  to  the  nearest  \°  or  \°. 

Members  of  the  Forest  Service  who  are  using  solars,  transits,  levels,  etc.,  have 
received  training  and  experience  in  the  care  and  use  of  such  instruments,  and  can 
execute  the  necessary  surveys  of  precision.  They  are  provided  with  advanced 
manuals  of  surveying  and  construction,  tables,  ephemerides,  etc. 

5 


6          INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

errors  usually  balance  themselves,  and  they  are  quickly 
discovered  by  the  trained  operator,  who  will  know  how 
to  make  allowance  for  them,  if  necessary.  The 
unskilled  or  careless  man  will  sometimes  read  the  wrong 
end  of  the  compass  needle;  read  the  graduated  ring 
dial  from  the  wrong  direction ;  make  a  mistake  in  enter- 
ing the  reading  in  his  notebook,  or  perpetrate  some 
other  palpable  blunder  which  will  throw  doubt  over 
the  whole  work  and  make  a  resurvey  necessary. 

Certain  fundamental  principles  underlie  all  surveys. 
We  may  assume  a  piece  of  land  the  location,  extent,  and 
contour  of  which  are  unknown.  First  of  all  the  survey 
should  determine  its  location,  shape,  and  area,  and  if 
necessary  its  topography,  and  any  other  essential 
data.  As  in  logic,  one  should  start  from  something 
which  is  known  to  determine  something  which  is 
unknown.  The  line  which  connects  an  unknown  point 
with  a  known  point  is  called  a  tie,  and  as  soon  as  the 
tie  is  run  the  position  of  the  unknown  point  is  estab- 
lished. A  line  run  around  a  tract  of  land  is  called  a 
boundary  line,  and  the  angles  on  this  line  are  called 
corners,  stations,  posts,  or  stakes,  according  to  the  local 
or  established  terms.  It  is  not  always  necessary  to 
run  the  boundaries  of  a  tract  to  determine  its  position 
and  area.  A  base  line  might  be  run  across  it  with  ordi- 
nates  on  either  side  extending  to  the  limits  of  the  tract. 
Or  if  the  tract  is  a  small  watershed,  lines  might  be 
traversed  up  all  of  the  streams  and  drainage  lines,  or 
the  area  might  be  divided  into  squares  and  fractions  of 
squares,  similar  to  land-survey  sections.  Still  another 
way  will  be  described  under  the  head  of  "Plane  table." 


INSTRUMENTS  USED.  7 

The  method  to  be  employed  depends  upon  the  purpose 
of  the  survey,  but  no  matter  what  method  is  used,  the 
survey  will  fail  in  its  primary  purpose  if  it  does  not 
show  the  location,  position,  form,  and  size  of  the  tract 

surveyed. 

INSTRUMENTS    USED. 

Three  kinds  of  instruments  are  used  in  surveying, 
viz:  For  determining  azimuth  or  horizontal  angles;  for 
determining  grade  or  vertical  angles;  for  determining 
distances.  The  horizontal  deflection  of  a  line  is  always 
expressed  in  degrees.  The  vertical  deflection  of  a  line 
is  generally  expressed  in  per  cent.  The  length  of  a  line 
in  Government  land  surveying  is  always  expressed  in 
chains  (66  feet).  The  altitude  above  sea  level  is 
expressed  mfeet. 

The  principal  instrument  for  determining  azimuth  is 
the  magnetic  compass,  which,  although  of  very  simple 
construction,  will  be  absolutely  misleading  to  anyone 
who  uses  it  without  understanding.  Suppose,  for 
instance,  a  good  compass,  manufactured  and  adjusted 
in  some  eastern  factory  or  in  Europe,  should  be  taken 
to  the  Pacific  coast.  It  would  undoubtedly  indicate 
the  direction  of  the  magnetic  currents  at  any  time  and 
place  that  it  might  be  used,  but  its  needle  would  not 
point  north  and  south  and  probably  would  not  hang 
level  on  the  center  pivot.  The  latter  defect  is  quickly 
remedied  by  moving  a  little  sliding  weight,  which 
should  be  on  the  south  end. of  the  needle. 

Sight  compasses  are  constructed  so  that  they  may 
be  sighted  upon  a  distant  object  and  the  magnetic  di- 
rection is  determined  .by  reading  the  degree  indicated 
on  the  ring  dial  by  the  north  end  of  the  needle. 


8         INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

Vernier  compasses  are  provided  with  a  revolving 
graduated  ring  dial  which  may  be  set  according  to  the 
magnetic  variation,  thus  reducing  the  reading  to  true 
north  instead  of  magnetic  north. 

Clinometer  compasses  are  provided  with  a  small  pen- 
dulum hung  from  the  center  pivot,  which  is  used  to 
determine  a  vertical  angle. 

Prismatic  compasses  are  sight  compasses  with  a 
" floating"  dial  which  may  be  held  in  the  hand.  The 
sight  is  taken  and  the  direction  is  read  in  the  same 
operation. 

Mirror  compasses  are  provided  with  a  reflecting  sur- 
face on  the  inside  of  a  hinged  cover,  and  the  reflec- 
tion of  the  reading  is  noted  at  the  time  the  sight  is  taken. 

Alidade  compasses  are  provided  with  at  least  one 
straight  edge  parallel  to  the  line  of  sight.  The  bottom 
of  the  compass  is  smooth  so  that  the  instrument  may 
be  laid  upon  a  map  and  the  straight  edge  used  as  a 
ruler. 

Solar  compasses  are  provided  with  a  special  attach- 
ment which  can  be  revolved  independent  of  the  com- 
pass for  taking  observations  on  the  sun  and  determin- 
ing the  cardinal  direction  without  using  the  compass 
needle. 

Compasses  are  also  used  as  a  part  of  the  equipment 
of  transits,  levels,  and  plane  tables,  and  in  such  cases 
these  instruments  should  be  constructed  of  nonmagnetic 
materials,  in  order  that  the  needle  may  not  be  deflected. 
Iron,  nickel,  cobalt,  and  manganese  are  the  most  mag- 
netic substances. 

The  instruments  for  determining  grade  or  vertical 
angles  are: 


STANDARD   COMPASS.  9 

The  grademeter; 

The  Locke  hand  level;  and 

The  Abney  reflecting  level,  which  is  provided  with  a 
vertical  arc,  graduated  either  to  per  cent,  degrees,  or 
ratio  of  slope,  according  to  the  purpose  for  which  it  is 
used. 

The  unit  of  land  measure  is  the  standard  surveyor's 
chain  of  66  feet.  For  some  classes  of  work  steel  band 
chains  or  steel  tapes  are  found  more  convenient  and 
economical,  because  they  are  lighter  and  greater 
lengths  can  be  dragged  over  the  ground,  thus  effecting 
a  saving  i.n  pinning  and  tallying.  Tapes  are  usually 
graduated  in  feet,  and  when  they  are  used  it  is  necessary 
to  reduce  the  measurements  to  standard  chains,  in 
order  that  they  may  conform  with  the  official  land  sur- 
veys. In  some  regions  the  best  means  for  determining 
distances  are  the  stadia  transit  and  rod.  These  in- 
struments are  used  by  specially  trained  men,  and  are 
therefore  not  described  here. 

FOREST    SERVICE    STANDARD   COMPASS. 

Figure  1  shows  the  surveying  compass  which  has 
been  adopted  by  the  Forest  Service  for  the  use  of  field 
men  in  making  forest  surveys  and  maps.  Very  accu- 
rate work  can  be  done  with  this  instrument  if  properly 
used,  and  for  this  reason  requisitions  for  transits  should 
not  be  made  unless  there  is  a  special  need  for  using  a 
still  higher  grade  instrument.  The  principal  features 
of  this  standard  compass  are  as  follows: 

The  sights  are  very  tall,  and  therefore  admit  of  Use 
on  steep  hillsides  or  in  taking  observations  on  Polaris. 
The  hair  sight  may  be  repaired  easily  by  threading 
through  the  holes  at  A  and  B.  If  after  long  use  the 


10      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

sights  work  too  freely  they  may  be  tightened  by  the 
nut  G. 


FIG.  1.— Forest  Service  standard  compass. 

The  base  of  the  instrument  is  an  accurate  square, 
beveled  and  graduated  as  a  protractor  on  two  sides 


STANDARD  COMPASS.  11 

and  to  inch  scales  on  two  sides.  One  of  these  scales  is 
Forest  Atlas  standard  of  1  inch  to  1  mile,  and  is 
divided  into  eighths,  each  of  which  represents  10  chains. 
The  other  scale  is  decimal.  The  base  supports  two 
levels,  D,  set  at  right  angles  to  each  other,  each  being 
adjustable  by  means  of  small  screws  and  a  center  point 
on  which  they  rock. 

The  clamp  E  is  a  milled  nut  which  operates  to  lift 
the  needle  from  the  center  pin  when  the  compass  is  not 
in  use.  It  works  so  easily  on  a  screw  that  the  azimuth 
of  the  instrument  need  not  be  disturbed  when  the  needle 
is  undamped  or  clamped.  The  thread  is  riveted  on  the 
top  so  that  the  nut  will  not  come  off  and  be  lost. 

The  needle  F  is  of  blue  steel  and  is  provided  on  its 
south  end  with  a  small  brass  weight,  which  may  be 
pushed  toward  or  away  from  the  center  if  it  becomes 
necessary  to  make  the  needle  hang  horizontal  and 
counteract  the  magnetic  dip  in  any  locality.  Of  course 
the  needle  should  be  removed  from  the  center  pivot 
when  this  is  done.  The  base  dial  is  reenforced  at  H  to 
hold  the  center  pivot  more  securely.  It  is  engraved 
to  show  (1)  the  cardinals,  (2)  a  half  circle  of  degrees 
for  the  clinometer,  and  (3)  70°  of  variation,  including 
east  and  west.  The  ring  dial  /  is  graduated  to  degrees 
reading  from  zero0,  from  north  and  south,  to  90°  at 
east  and  west.  It  carriers  a  vernier,  J,  which  reads 
against  the  variation  graduation  on  the  base  dial.  The 
cover  is  of  heavy  plate  glass  and  is  held  in  place  by  a 
graduated  and  slotted  rim,  K,  which  also  revolves  in 
azimuth. 

The  clinometer  consists  of  a  weighted  pendulum,  L, 
which  hangs  on  th,e  center  pivots  and  is  provided  with 


12 

a  pointer  which  reads  against  a  graduation  on  the  base 
dial. 

The  edges  M  and  N  are  perpendicular  to  each  other, 
and  the  line  0  P  is  parallel  to  the  line  of  sight  and 
may,  therefore,  be  used  as  an  alidade. 

The  above  description  covers  that  portion  of  the  in- 
strument which  is  used  upon  a  plane  table  either  for 
ordinary  compass  work  or  for  mapping  on  the  plane- 
table  sheet.  The  instrument  is,  however,  provided 
with  a  ball-and-socket  attachment  so  that  it  may  be 
used  upon  a  Jacob  staff,  tripod,  or  more  conveniently 
held  in  the  hand  if  used  as  a  hand  compass  for  rough 
cruising.  These  parts  are  shown  in  the  illustration ;  Q, 
a  cone-bearing  containing  the  spindle,  which  may  be 
clamped  by  the  screw  R;  the  ball  8  is  held  by  the  socket 
cover  T,  which  screws  upon  the  mounting  U. 

When  this  instrument  is  used  on  the  plane  table  the 
proceeding  is  as  follows: 

The  sights  having  been  raised  and  the  instrument 
laid  on  the  table,  the  table  is  leveled  by  observing  the 
bubbles.  The  variation  having  been  set  off,  the  table 
is  oriented  with  the  compass  needle,  which  should  read 
zero  at  the  north  end.  Then  sights  may  be  taken  upon 
all  the  objects  to  be  mapped,  using  the  edge  0  P,  or  the 
opposite  parallel  edge,  as  an  alidade.  The  distances 
may  be  measured  with  the  scale. 

When  used  as  a  surveyor's  compass  the  leveling  is 
done  by  means  of  the  ball  and  socket  8  and  T,  and  the 
compass  is  revolved  in  azimuth  by  loosening  the  clamp 
screw  R. 

As  a  clinometer  for  measuring  vertical  angles,  the 
edge  M  may  be  laid  upon  a  slope  and  the  pendulum 


STANDARD   COMPASS.  13 

will  show  the  number  of  degrees  of  dip  or  rise.  This 
is  not  the  same  as  ' '  per  cent  of  grade."  The  difference 
is  shown  on  page  40.  Another  method  is  to  lay  the 
edge  M  on  the  level  plane-table  board  and,  revolving 
the  rim  vertically,  take  a  sight  through  the  slots  K. 
The  angle  of  dip  or  rise  may  then  be  very  closely  ap- 
proximated by  reading  the  graduation  on  the  rim.  In 
some  of  these  instruments  the  cover  of  the  socket,  at 
the  ball  joint,  is  cut  away  on  one  side,  permitting  the 
spindle  to  be  tipped  over  and  the  compass  revolved  in 
a  vertical  plane.  The  sights  may  then  be  used  in  con- 
nection with  the  clinometer.  This  altered  socket  will 
be  issued  when  specially  requisitioned. 

Right  angles  may  be  turned  accurately  without  the 
use  of  the  compass  by  two  methods:  (1)  By  drawing  a 
line  on  the  plane-table  sheet  on  the  edges  0  P  and  then 
turning  the  instrument  90°  until  the  edge  M  coincides 
with  the  line,  or  (2)  the  slots  ^may  be  used  without 
moving  the  instrument,  as  they  are  placed  exactly  90° 
apart. 

This  instrument  should  give  good  results  if  used  and 
treated  with  the  care  which  is  necessary  for  any  well- 
made  and  carefully  adjusted  instrument.  The  cus- 
todian should  keep  it  clean,  but  should  not  oil  it,  though 
it  may  be  wiped  occasionally  with  a  slightly  greasy 
piece  of  muslin.  The  needle  should  always  be  clamped 
when  not  in  use,  and  the  hair  sight  should  always  be 
closed  down  first  so  that  it  will  be  protected  by  the 
slot  sight.  The  cover  glass  may  be  removed  by  tak- 
ing off  the  sights  and  then  the  surrounding  rim,  which 
is  provided  with  small  brass  screws  which  travel  in  a 
channel  cut  into  the  outside  of  the  compass  box.  It  is 


14      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

not  necessary  to  remove  the  glass  in  order  to  sharpen 
the  center  pivot.  This  may  be  done  by  unscrewing  it 
from  the  under  side  of  the  compass  after  the  needle 
has  been  clamped,  although  this  must  be  done  very 
carefully,  so  that  the  clinometer  pendulum  will  not 
move  out  of  place;  otherwise  it  will  be  necessary  to 
remove  the  cover  glass. 

In  case  of  any  serious  injury  to  any  instrument,  it 
should  be  returned  to  the  property  clerk  at  Ogden  for 
repairs. 

The  instrument  should  not  be  kept  near  large  bodies 
of  iron,  nor  exposed  to  electric  motors  or  generators. 
Compass  needles  are  frequently  demagnetized  by  being 
carried  in  a  valise  in  an  electric  car  and  being  set 
down  over  a  powerful*  motor,  because  the  needle  is 
clamped  (as  it  should  be)  while  being  carried.  On  the 
other  hand,  the  magnetism  of  a  needle  may  be  strength- 
ened by  laying  the  compass,  with  the  needle  undamped, 
near  a  direct-current  motor  or  generator  or  strong 
magnet.  A  better  plan  is  to  unclamp  the  needle,  and 
after  it  has  found  its  bearing,  to  clamp  it  and  leave  it 
to  the  influence  of  the  magnetic  current.  In  this  way 
the  continued  quiver  of  the  needle  will  not  dull  the 
center  pivot. 

Do  not  allow  the  needle  to  be  deflected,  while  being 
read,  by  an  ax,  jackknife,  pencil  tip,  the  metal  band  of 
a  hat,  or  other  metal. 

THE    POCKET   COMPASS. 

The  Forest  Service  standard  pocket  compass  is  a 
strong  and  serviceable  instrument  for  cruising  or  re- 
tracing survey  lines.  Instructions  for  its  proper  use 
are  engraved  upon  the  base  dial,  as  shown  in  figure  2. 


STANDARD  POCKET   COMPASS. 


15 


FIG.  2.— Standard  pocket  compass. 


16      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

MAGNETIC   NEEDLE. 

It  is  unfortunate  that  all  makers  of  surveying  instru- 
ments do  not  have  a  uniform  method  of  designating  the 
north  or  south  end  of  compass  needles,  but  that  the 
surveyor  must  learn  and  remember  whether  the  blue  or 
white,  or  the  weighted  or  cross-barred  end  of  the  needle 
is  the  one  which  points  northward.  Some  small  com- 
passes also  differ  in  the  positions  of  the  E.  and  W.  ac- 
cording to  the  use  which  is  to  be  made  of  them.  If 
they  are  to  be  used  as  sight  compasses,  they  should 
have  the  E.  on  the  left  side  of  the  dial.  In  good  weather, 
when  the  sun  shines  or  where  distant  features  of  the 
landscape  are  in  constant  view,  there  is  little  chance  of 
error  by  reading  the  wrong  end  of  the  needle,  but  there 
are  many  conditions  under  which  the  compass  alone 
must  be  the  guide. 

VARIATION. 

It  will  be  seen  by  the  map  (fig.  3)  that  only  along  one 
line  in  the  United  States,  the  so-called  "line  of  no  varia- 
tion/' does  the  needle  point  due  north.  This  line  is 
not  stationary,  but  has  a  slow  movement  westward. 
At  all  other  points  in  the  United  States  the  north  end 
of  the  needle  is  deflected  toward  the  "line  of  no  varia- 
tion." In  the  North  Atlantic  States  the  variation  of 
the  north  end  of  the  needle  is  to  the  west,  and  a  sur- 
veyor at  Augusta,  Me.,  would  enter  in  his  field  notes 
"variation  16°  west."  At  Portland,  Oreg.,  the  entry 
would  be  "variation  21J°  east."  The  maximum  an- 
nual change  of  variation  in  the  United  States  is  only 
about  5  minutes.  On  the  Pacific  coast  it  is  only  1 
minute. 


MAGNETIC    NEEDLE. 


17 


°— 12 2 


18      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 


•  MIZAR 


If  a  survey  is  to  be  made  in  a  region  which  has  not 
been  subdivided  by  Government  land  surveys  or  where 
the  variation  of  the  needle  is  not  known,  then  the  sur- 
veyor must  do  one  of  three  things. 
He  should  if  possible  find  the 
variation  by  observing  the  Pole 
Star,  of  which  approximate  bear- 
ings are  given  (Table  1)  at  9  p.  m. 
during  the  year ;  or  he  may  obtain 
the  true  meridian  by  observing  the 
sun  at  apparent  noon.  If  neither 
can  be  done,  a  variation  may  be 
assumed  after  examination  of 
figure  3,  and  this  assumed  varia- 
tion should  be  entered  in  the  field 
notes  and  shown  on  the  map,  with 
the  date  when  the  map  is  pre- 
pared. 


POLARIS  I -N-POLE 


OBSERVING   POLARIS. 


. 

T:  / 


The  Pole  Star  is  not  exactly 
above  the  North  Pole  of  the 
earth,  but  its  bearing  is  due  north 
twice  a  day,  and  an  observation 
of  it  at  one  of  these  times  will 
give  a  true  meridian.  Mizar,  a 
double  star  in  the  bend  of  the 
handle  of  the  Big  Dipper  is  either  above  or  below  the 
Pole  Star  at  these  times.  The  same  is  true  of  the  star 
d  (Delta)  in  the  constellation  Cassiopeia.  (See  fig.  4.) 
At  all  other  hours  the  Pole  Star  has  a  bearing  either 


FIG.  4.—  Position  of  the  Big 
Dipper  and  Cassiopeia  when 
Polaris  is  due  north.  If  the 
figure  is  held  upside  down  it 
shows  the  reverse  position  in 
which  Polaris  is  also  due 
north. 


OBSERVING  POLARIS.  19 

east  or  west  of  true  north.  It  is  most  convenient  to 
take  a  sight  on  Polaris  at  9  p.  mv  and  for  this  reason 
the  accompanying  table  was  prepared.  The  sight 
having  been  taken,  it  will  be  easy  to  turn  the  compass 
to  true  north  and  ascertain  the  variation. 


20      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 


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OBSERVING  THE  SUN  AT  NOON.  21 

OBTAINING  A  TRUE  MERIDIAN  BY  OBSERVING  THE 
SUN  AT  APPARENT  NOON. 

In  addition  to  the  instructions  given  on  pages  16  to 
19,  there  is  a  method  of  obtaining  a  true  meridian 
by  observing  the  sun  with  a  sight  compass  at  the  exact 
time  it  is  due  south.  The  time  of  this  southing  is  called 
apparent  noon  and  changes  from  day  to  day.  It  is  not 
the  same  as  local  mean  noon,  nor  standard  time  noon. 
It  is  best  to  set  your  watch  for  local  mean  time,  since 
you  can  then  observe  a  southing  at  the  time  given  in 
Table  2.  If  your  watch  is  set  for  standard  time,  it  will 
be  necessary  to  set  it  ahead  or  back  by  adding  or  sub- 
tracting a  correction,  according  as  the  longitude  of 
your  station  is  either  east  or  west  of  one  of  the  standard 
meridians.  These  are: 

Local  mean  time  at — 

Longitude    75°==Eastern  standard  time. 
Longitude    90°=Central  standard  time. 
Longitude  105°=Mountain  standard  time. 
Longitude  120°=Pacific  standard  time. 

The  correction  for  a  degree  of  longitude  is  4  minutes 
of  time;  the  correction  for  a  minute  of  longitude  is  4 
seconds  of  time.  To  illustrate:  The  local  mean  time 
in  longitude  108°  will  evidently  be  12  minutes  behind 
Mountain  standard  time,  or  48  minutes  ahead  of 
Pacific  standard  time.  The  local  mean  time  in  longi- 
tude 114°  35'  will  be  21  minutes  and  40  seconds  ahead 
of  Pacific  standard  time.  The  method  is: 

Pacific  standard  time  is  for  longitude  120°  00' 

Local  mean  time  is  required  for  longitude    114°  35' 

The  difference  in  longitude  is  5°  25' 

Then  5°         25' 

Multiplied  by  4  4 

Gives  20  m.  100  s.,  or  21  m.  40  s. 


22      INSTRUCTIONS  TOR  MAKING  FOREST  SURVEYS,  ETC. 
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INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC.  23 

PLANE  TABLE. 

For  making  any  map  the  plane  table  is  the  best  in- 
strument in  use.  Instead  of  taking  notes,  as  in  run- 
ning compass  lines,  the  surveyor  plats  his  work  in  the 
field  and  can  thus  always  see  the  progress  made.  Er- 
rors and  omissions  are  discovered  quickly  and  rectified. 

The  paper  upon  which  the  map  is  to  be  made  is  fast- 
ened to  the  plane-table  board  by  thumb  tacks,  and  upon 
it  rests  the  alidade,  a  straightedge  or  ruler  with  fold- 
ing sights  like  a  compass.  From  a  point  on  the  paper 
which  represents  the  starting  point  on  the  ground  over 
which  the  table  is  standing  the  surveyor  draws  lines 
on  the  paper  with  the  alidade  to  the  various  topographic 
features  which  are  to  be  mapped.  From  start  to  finish 
of  the  survey  it  must  at  all  stations  retain  the  same 
orientation — that  is  to  say,  at  every  station  where  the 
table  is  set  up  its  sides  must  be  exactly  parallel  to  its 
position  at  the  original  station. 

There  are  several  methods,  all  based  upon  the  same 
principles.  If  an  isolated  block  of  forest  is  to  be 
bounded  by  a  survey,  the  method  would  be: 

Set  up  at  A  with  one  side  of  the  table  bearing  ap- 
proximately north  and  south.  As  A  is  near  the  south- 
east corner  of  the  tract,  begin  to  draw  at  the  correspond- 
ing place  on  the  paper.  With  the  alidade  draw  a  line 
from  A  toward  B.  Measure  the  distance  AB  on  the 
ground  and  scale  the  proportionate  distance  on  the 
paper.  Set  the  table  at  B.  With  the  alidade  on  the 
drawn  line  take  a  backsight  on  A.  The  table  will  then 
be  oriented  or  parallel  to  its  position  when  at  A.  Draw 
a  line  on  the  paper  from  B  toward  C.  Measure  it  and 


24      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

scale  on  the  map.  Proceed  as  before,  and  the  result  will 
be  a  map  which  will  truly  represent  the  lines  on  the 
ground.  (See  fig.  5.) 

In  this  case  the  points  C  and  D  were  not  visible  from 
A,  but  if;  instead  of  being  a  block  of  forest,  the  area  were 
an  open  meadow,  then  a  second  method  would  be  used. 


FIG.  5.— Plane-table  method  in  which  the  table  is  set  up  at  all  the  stations. 

Set  up  at  A.  Draw  lines  to  B,  C,  D,  and  E.  Meas- 
ure AB.  Set  up  at  B.  Orient  on  A.  Draw  lines  to 
C,  D,  and  E.  The  intersections  of  the  line  will  give 
the  other  three  points.  The  line  AB  is  a  base  line. 
(See  fig.  6.) 

The  third  method  is  an  extension  of  the  second  and 
involves  some  near-by  points  which  can  not  be  located 


PLANE  TABLE. 


25 


from  the  base  line.  From  A  and  B  the  points  G,  D,  E, 
and  F  are  intersected,  and  one  sight  is  taken  on  G, 
which  is  obviously  too  nearly  in  line  with  the  base  line 
to  be  accurately  intersected.  Subsequently  the  table 
is  set  up  at  C  and  oriented  by  taking  sights  on  A,  B, 
D}  E,  and  F.  It  is  then  easy  to  intersect  G,  and  also  get 


\ 


\ 


\ 


FIG.  6. — Plane-table  method  in  which  the  table  is  set  up  at  two  stations  and  the 
remaining  three  are  located  by  intersections. 

a  sight  on  H,  which  was  not  visible  before.     77  may  be 
intersected  from  G.     (See  fig.  7.) 

A  fourth  method  is  employed  when  the  table  must 
be  set  up  at  an  unknown  point  from  which  three  or 
more  known  points  are  visible.  This  is  the  "  three- 
point  problem,"  in  which  the  suveyor  "picks  up"  his 


26      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

location.  Suppose  that  (7,  D,  and  E  were  located  by 
the  third  method  and  are  high  and  well-defined  peaks. 
They  form  a  triangle  which  can  be  accurately  platted 
on  the  paper,  and  the  best  plan  is  to  prick  in  the  points 
with  a  fine  needle.  The  surveyor  will  then  proceed 


FIG.  7.— Plane-table  method  of  locating  points  on  both  sides  of  a  base  line  which  are 
to  be  occupied  later  and  the  survey  extended. 

by  setting  up  the  table  at  the  point  which  is  to  be 
located  and  from  which  he  can  see  the  three  peaks. 
Orient  approximately  by  compass.  With  the  alidade 
draw  lines  from  each  peak  toward  the  point  of  set-up. 
If  the  three  lines  intersect,  the  desired  point  is  located, 


PLANE  TABLE. 


27 


except  as  noted  below.  If  the  lines  do  not  intersect,  the 
orientation  may  be  changed  until  they  do,  but  an  easier 
plan  is  to  fasten  a  piece  of  tracing  cloth  on  the  table 
and  assume  a  point  from  which  the  lines  may  be  drawn 
toward  the  peaks.  The  tracing  may  then  be  shifted 
over  the  paper  to  find  a  position  at  which  the  lines  will 


FIG.  8. — Plane-table  method  of  finding  location  from  three  points. 

exactly  cover  the  three  needle  holes  on  the  paper.  This 
method  is  reliable  when  the  desired  location  is  within 
the  triangle,  but  it  is  useless  when  the  table  is  set  up  on 
or  near  a  circle  which  would  pass  through  the  three 
peaks.  For  this  reason  four  or  more  points  should  be 
used  if  possible.  (See  fig.  8.) 


28      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 
ANEROID   BAROMETER. 

The  pocket  aneroid  barometer  is  not  a  very  accurate 
instrument,  but  satisfactory  results  may  generally  be 
obtained  by  using  the  following  method :  Two  aneroids 
are  necessary.  Both  should  be  compared  and  set  at 
some  established  elevation,  such  as  a  bench  mark  of  the 
Geological  Survey  or  at  a  railway  station.  Any  neces- 
sary correction  may  be  made  by  sliding  the  rim  or  by 
means  of  the  small  screw  on  the  back  of  the  barometer, 
which  will  move  the  hand  to  the  proper  reading.  After 
arriving  at  the  camp  from  which  the  survey  is  to  be 
made  both  aneroids  should  be  read  and  the  readings 
entered  in  the  notes.  One  aneroid  should  be  kept  in 
camp  while  the  other  is  used  in  the  field,  and  they 
should  be  compared  twice  a  day,  say,  at  7  a.  m.  and  7 
p.  m.  The  camp  barometer  will  then  show  the  change 
in  atmospheric  pressure  from  time  to  time  during  the 
survey,  and  the  difference  between  the  two,  when  the 
field  barometer  is  being  used  at  a  distance,  will  give 
the  difference  in  elevation  between  the  camp  and  the 
point  where  the  field  barometer  was  read.  If  the  two 
barometers  agree  in  the  morning  and  do  not  agree  at 
evening  the  difference,  if  material,  may  be  proportioned 
during  the  day's  notes,  assuming  the  camp  barometer 
to  be  correct.  The  scale  of  "mercury  inches,"  gen- 
erally graduated  on  aneroids,  is  not  to  be  used.  If  a 
barometer  gets  out  of  order  or  does  not  give  satisfaction, 
it  should  be  returned  to  the  property  clerk.  Do  not 
attempt  to  repair  it  nor  oil  any  of  its  parts. 


STANDARD  HYPSOMETER. 


29 


METHOD  OF  USING  THE  FOREST  SERVICE  STANDARD 
HYPSOMETER   AND    GRADEMETER. 

Stand  100  feet  from  the  base  of  the  tree  which  is  to 
be  measured. 

The  observer  inserts  the  fingers  of  his  left  hand  into 
the  loop  of  leather  straps  attached  to  the  back  of  the 
hypsometer,  with 
both  straps  inside 
of  the  hand  and 
the  instrument  on 
the  back  of  the 
lingers.  Closing 
the  hand  enables 
him  to  grasp  the 
straps  firmly. 
The  thumb  is  in 
such  a  position  as 
readily  to  press 
down  the  small 
brass  knob  which 
releases  the  cir- 
cular pendulum 
on  the  inside  of 
case.  By  an  easy 
motion  of  the  el- 
bow, the  small 
peephole  is 
brought  close  to  the  eye  of  the  observer.  The  square 
window,  directly  opposite  the  peephole,  is  pointed  toward 
the  object  whose  height  is  to  be  determined.  The  light 
enters  from  the  large  window  on  the  face  of  instrument. 


FIG.  9.— Method  of  sighting  with  standard  hypsometer. 


30      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

With  the  thumb  pressing  the  release,  the  sight  is 
taken  on  the  object  and  the  height  is  read  at  the  same 
time;  or  the  thumb  may  be  lifted,  and  the  pendulum 
thus  being  clamped,  the  height  of  the  tree  may  be  read 
through  the  window. 

If  the  observer  stands  only  50  feet  from  the  tree  the 
reading  must  be  divided  by  2.  If  he  stands  200  feet 
away  it  must  be  multiplied  by  2,  and  proportionately 
for  other  distances. 

The  reading  gives  the  height  above  the  level  of  the 
eye.  Allowance  must  be  made  if  the  observer's  eye  is 
above  or  below  the  stump  height  of  the  tree. 

The  notebook  and  pencil  are  held  in  the  right  hand 
while  an  observation  is  being  taken,  and  the  notebook 
is  passed  to  the  left  hand  when  the  observation  is 
entered.  The  hypsometer  being  on  the  back  of  the 
fingers  allows  free  play  for  the  thumb,  palm,  and  ends 
of  the  fingers  of  the  left  hand  to  hold  the  notebook. 
In  moving  from  station  to  station  the  right  hand  is 
then  free  to  assist  in  getting  through  the  brush  or  in 
crossing  logs. 

The  circular  pendulum  is  graduated  to  tangents. 
Therefore  it  may  be  used  to  determine  the  per  cent  of 
grade  of  a  road  or  trail.  For  this  purpose  sights  may 
be  taken  downhill  as  well  as  uphill.  No  conversion  of 
figures  is  necessary.  If  the  reading  is  10  the  grade  is 
10  per  cent.  It  will  not  hereafter  be  necessary  to  use 
pocket  levels  for  this  class  of  work,  since  the  hypsom- 
eter-grademeter  answers  every  purpose. 


MEASUREMENTS.  31 

DETAILS  OF  SURVEYING. 
MEASUREMENTS. 

The  most  frequent  source  of  error  in  pacing,  chaining, 
or  steel  taping  is  in  counting  the  tallies — assuming  that 
the  mechanical  part  of  the  work  is  well  done.  The 
memory  should  not  be  trusted.  The  only  safe  plan  is 
to  enter  each  tally  in  the  field  notes  as  soon  as  that  tally 
is  completed  and  the  pins  or  stakes  have  been  counted 
by  both  chainmen  and  before  the  next  tally  is  begun. 
When  timber  is  being  estimated  along  the  survey  line 
this  error  is  not  likely  to  occur,  as  the  numbers  on  the 
timber  sheets  are  a  check  upon  the  work. 

If  a  pair  of  amateur  chainmen  went  over  some  open 
level  country  and  reported  a  distance  of  174.62  chains, 
an  error,  if  one  existed,  would  probably  be  found  in  the 
"tens"  or  tallies,  and  a  resurvey  would  give  164.62  or 
184.62  chains.  The  standard  chain  has  a  length  of  66 
feet.  If  any  other  unit  of  linear  measure  is  used,  it 
must  be  made  clear  in  the  notes. 

For  some  classes  of  work  steel  tapes  or  "  band  chains  " 
are  preferable,  because,  being  lighter,  they  can  be  longer 
and  stretched  straight er  than  chains. 

CONCERNING    ACCURACY. 

The  field  work  of  the  Forest  Service  extends  over 
millions  of  acres  of  wild,  very  rough,  and  frequently 
almost  inaccessible  lands.  In  the  surveying  and  map- 
ping of  such  lands,  it  should  be  understood  that  the  term 
11  accuracy"  does  not  call  for  the  degree  of  precision 
which  would  be  applied  to  city  lots  having  a  value  of 


32      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS.  ETC. 


$1,000  per  square  foot.  The  surveys  of  the  Forest 
Service  call  for  practical  accuracy,  rather  than  technical 
correctness  or  precision. 

Figure  10  shows  the  changing  areas  in  the  survey  of 
a  square  mile  in  which  there  is  a  compass  error  of  one- 
fourth  degree.  When  measurements  close,  but  not  at 
right  angles,  the  result  is  a  diamond,  and  the  loss  in  area  is 
about  0.02  of  an  acre,  representing  a  value  of  only  5  or 
10  cents.  In  a  converging  section  the  loss  may  be  2.80 


^0- 

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SO.OOChs. 

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ACRES 

GO.OOCha. 

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I 

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Perfect  square.  Diamond.  Converging  quadrangle. 

FIG.  10.— Areas  of  a  section  containing  a  compass  error  of  0.25  degree. 

acres,  but  in  either  instance  such  a  survey  is  considered 
to  inclose  a  conventional  section  of  640  acres,  and  this 
will  also  be  the  case  if  there  is  an  excess  acreage  to  the 
same  extent.  To  survey  a  perfect  square  would  be  very 
expensive  and  not  justifiable  in  view  of  the  trifling 
values  involved. 

TRAVERSE. 

When  a  survey  is  run  along  a  road  or  stream,  or  fol- 
lows the  crest  of  a  divide,  the  line  "meanders''  and 
consists  of  a  number  of  short  courses  and  distances. 
The  courses  are  read  from  the  north  end  of  the  needle 
and  platted  on  the  map  with  a  protractor.  Whenever 


TRAVERSE.  33 

the  actual  change  in  latitude  or  departure  (longitude) 
is  desired,  it  may  be  computed  with  the  traverse  table. 
In  platting  with  the  protractor  care  should  be  used 
that  all  the  angles  are  set  off  from  the  same  meridian, 
otherwise  the  errors  will  accumulate.  The  angles  of 
all  courses  in  surveying  are  measured  from  the  north 
and  south  cardinals  toward  the  east  or  west,  and  they 
should  be  platted  the  same.  The  figures  on  some  pro- 
tractors are  misleading  in  this  respect. 

23682°— 12 3 


34      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 


TABLE  3. —  Traverse. 


Course. 

Dist 

~Latr 

.  1. 
~Dep7 

Dist.  2. 

Dist.  3. 

Dist.  4. 

Dis 
"LatT 

t.  5. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Di'p. 

Dep". 

0  15 

1.0000 

0.0044 

2.0000 

0.0087 

3.0000 

0.  0131 

4.0000 

0.  0175 

5.  0000 

0.0218 

89  45 

30 

0000  0087 

1.  9999 

0175 

2.  9999 

0262 

3.  9998 

0349 

4.  9998 

0436 

30 

45 

0.  9999  0131 

9998 

0262 

9997 

0393 

9997 

0524 

9996 

0654 

15 

1  0 

9998  0175 

9997 

0349 

9995 

0524 

9994 

0698 

9992 

0873 

89  0 

15 

9998  0218 

9995 

0436 

9993 

0654 

9990 

0873 

9988 

1091 

45 

30 

9997  02U2 

9993 

0524 

9990 

0785 

9986 

1047 

9983 

1309 

30 

45 

9995  0305 

9991 

0611 

9986 

0916 

998] 

1222 

9977 

1527 

15 

2  0 

9994  0349 

9988 

0698 

9982 

1047 

9976 

1396 

9970 

1745 

88  0 

15 

9992  0393 

9985 

0785 

9977 

1178 

9969 

1570 

9961 

1963 

45 

30 

9990;  0436 

9981 

0872 

9971 

1309 

9962 

1745 

9952 

2181 

30 

45 

0.  9988  0.  0480 

1.9977 

0.  0900  2.  9965 

0.  1439 

3.  9954 

0.  1919 

4.  9942 

0.  2399 

15 

3  0 

9986,  0523 

9973 

1047 

9959 

1570 

9945 

2093 

9931 

2617 

87  0 

15 

9984;  0507 

9968 

1134 

9952 

1701 

9936 

2268 

9920 

2835 

45 

30 

9981|  0610 

9963 

1221 

9944 

1831 

9925 

2412 

9907 

3052 

30 

45 

9979  0654 

9957 

1308 

9936 

1962 

9914 

2616 

9893 

3270 

15 

4  0 

i*976  0698 

9051 

1395 

9927 

2093 

9903 

2790 

9878 

3488 

86  0 

15 

9973  0741 

9945 

1482 

9918 

2223 

9890 

2964 

9863 

3705 

45 

30 

9969 

0785 

9938 

1569 

9908 

2354 

9877 

3138 

9846 

3923 

30 

45 

9966 

0828 

9931 

1656 

9897 

2484 

9863 

3312 

9828 

4140 

15 

5  0 

99G2 

0872 

9924 

1743 

9886 

2615 

9848 

3486 

9819 

4358 

85  0 

15 

0.  9958 

0.  0913 

1  .  9916 

0.  1830 

2.  9874 

0.  2745 

3.  9832 

0.  3660 

4.  9790 

0.  4575 

45 

30 

9954 

0958 

9908 

1917 

9862 

2875 

9816 

3834 

9770 

4792 

30 

45 

9950 

1002 

9899 

2004 

9849 

3006 

9799 

4008 

9748 

5009 

15 

6  0 

9945 

1045 

9890 

2091 

9836 

3136 

9781 

4181 

9726 

5226 

84  0 

15 

9941 

1089 

9881 

2177 

9S22 

3266 

9762 

4355 

9703 

5443 

45 

30 

9936 

1132 

9871 

2264 

9807 

3396 

9743 

4528 

9679 

5660 

30 

45 

9931 

1175 

9861 

2351 

9792 

3526 

9723 

4701 

9653 

5877 

15 

7  0 

9925 

1219 

9851 

2437 

9776 

3656 

9702 

4875 

9627 

6093 

83  0 

15 

9920 

1262 

9840 

2524 

9760 

3786 

9680 

5048 

9600 

6310 

45 

30 

9914 

1305 

9829 

2611 

9743 

3916 

9658 

5221 

9572 

6526 

30 

45 

0.  9909 

0.  1349 

1.981  70.  2697 

2.  9726 

0.  4046 

3.  9635 

0.  5394 

4.  9543 

0.  6743 

15 

8  0 

9903 

1392 

9805;  2783 

9708 

4175 

9611 

5567 

9513 

6959 

82  0 

15 

9897 

1435 

9793  2870 

9690 

4305 

9586 

5740 

9483 

7175 

45 

30 

9890 

1478 

9780  2956 

9670 

4434 

9561 

5912 

9451 

7390 

30 

45 

9884 

1521 

9767  3042 

9651 

4564 

9534 

6085 

9418 

7606 

15 

9  0 

9877 

1564 

9754  3129 

9631 

4693 

9508 

6257 

9384 

7822 

81  0 

15 

9870 

1607 

9740!  3215 

9610 

4822 

9480 

6430 

9350 

8037 

45 

30 

9863 

1650 

9726 

3301 

9589 

4951 

9451 

6602 

9314 

8252 

30 

45 

9856 

1693 

9711 

3387 

9567 

5080 

9422 

6774 

9278 

8467 

15 

10  0 

9848 

1736 

9696 

3473 

9544 

5209 

9392 

6946 

9240 

8682 

80  0 

15 

0.  9840 

0.  1779 

1.9681 

0.  3559 

2.  9521 

0.  5338 

3.  9302 

0.  7118 

4.  9202 

0.  8897 

45 

30 

9833 

1822 

9665 

3645 

9498 

5467 

9330 

7289 

9163 

9112 

30 

45 

9825 

1865 

9649 

3730 

9474 

5596 

9298 

7461 

9123 

9326 

15 

11  0 

9816 

1908 

9633 

3816 

944P 

5724 

9265 

7632 

9081 

9540 

79  0 

15 

9808 

1951 

9616 

3902 

9424 

5853 

9231 

7804 

9039 

9755 

45 

30 

9799 

1994 

9598 

3987 

939S 

5981 

9197 

7975 

8996 

9968 

30 

45 

9790 

203G 

9581 

4073 

9371 

6109 

9162 

8146 

8952 

1.0182 

15 

12  0 

,  9781 

2079 

9563 

4158 

9344 

6237 

9126 

8316 

8907 

0396 

78  0 

15 

9772 

2122 

9545 

4244 

9317 

6365 

9089 

8487 

8862 

0609 

45 

30 

9763 

21G4 

9526 

4329 

9289 

6493 

9052 

8658 

8815 

0822 

30 

45 

0.  9753 

0.  2207 

1.9507 

0.  4414 

2.  9260 

0.  6621 

3.  9014 

0.  8828 

4.  8767 

1.  1035 

15 

13  0 

9744 

2250 

9487 

4499 

9231 

6749 

8975 

8998 

8719 

1248 

77  0 

15 

9734 

2292 

9468 

4584 

9201 

6876 

8935 

9168 

8669 

1460 

45 

30 

9724 

2334 

9447 

4069 

9171 

7003 

8895 

9338 

8618 

1672 

30 

45 

9713 

2377 

9427 

4754 

9140 

7131 

8854 

9507 

8567 

1884 

15 

14  0 

9703 

2419 

9406 

4838 

9109 

7258 

8812 

9677 

8515 

2096 

76  0 

15 

9692 

2462 

9385 

4923 

9077 

7385 

8769 

9846 

8462 

2308 

45 

30 

9681 

2504 

9363 

5008 

9044 

7511 

8726 

1.0015 

8407 

2519 

30 

45 

9670 

2546 

9341 

5092 

9011 

7638 

8682 

0184 

8352   2730 

15 

15  f 

9659 

258S 

9319 

5176 

8978 

7765 

8637 

0353 

8296   2941 

75  0 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat, 

Dep.  Lat. 

r< 

Dist.  1. 

Dist.  2. 

Dist.  3 

Dist.  4. 

Dist.  5. 

Bourse. 

TRAVERSE. 


35 


TABLE  3. —  Traverse — Continued. 


Dist.  1. 

Dist.  2. 

Dist.  3. 

Dist.  4. 

Dist.  5. 

Course. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Dep.  j  Lat. 

Dep. 

Lat. 

Dep. 

0    / 

0     1 

15  15 

0.  9648 

0.2630 

1.9296 

0.  5261 

2.8944 

0.78913.8591 

1.0521 

4.  8239 

1.3151 

74  45 

30 

9636 

2672 

9273 

5345 

8909 

8017 

0690 

8182 

33C2 

30 

45 

9625 

2714 

9249 

5429 

8874 

8143 

8498 

08o8 

8123 

3572 

15 

16  0 

9613 

2756 

9225 

5513 

8838 

8269 

8450 

1025 

8063 

3782 

74  0 

15 

9600 

2798 

9201 

5597 

8801 

8395 

8402 

1193 

8002 

3991 

45 

30 

9588 

2840 

9176 

5680 

8765 

8520 

8353 

1361 

7941 

4201 

30 

45 

9576 

2882 

9151 

5764 

8727 

8646 

8303 

1528 

7879 

4410 

15 

17  0 

9563 

2924 

9126 

5847 

8689 

8771 

8252 

1695 

7815 

4619 

73  0 

15 

9550 

2965 

9100 

5931 

8651 

8896 

8201 

1862 

7751 

4827 

45 

30 

9537 

3007 

9074 

6014 

8612 

9021 

8149 

2028 

7686 

5035 

30 

45 

0.  9524 

0.  3049 

1.  9048 

0.  6097 

2.  8572 

0.  9146 

3.  8090 

1.2195 

4.  7020 

1.5243 

15 

18  0 

9511 

3090 

9021 

6180 

8532 

9271  8042 

2361 

7553 

5451 

72  0 

15 

9497 

3132 

8994 

6263 

8491 

9395J  7988 

2527 

7485 

5658 

45 

30 

9483 

3173 

8966 

6346 

8450 

9519 

7933 

2692 

7416 

5865 

30 

45 

9469 

3214 

8939 

6429 

8408 

9643  7877 

2858 

7347 

6072 

15 

19  0 

9455 

3256 

8910 

6511 

8366 

9767 

7821 

3023 

7276 

6278 

71  0 

15 

9441 

3297 

8882  6594 

8323 

9891 

7764  3188 

7204 

6485 

45 

30 

9426 

3338 

8853 

6676 

8279 

1.  0014 

7706  3352 

7132 

6690 

30 

45 

9412 

3379 

8824  6758 

8235 

0138 

76471  3517 

7059   6896 

15 

20  0 

9397 

3420 

8794  6840 

8191 

0261   7588|  3681 

6985   7101 

70  0 

15 

0.9382 

0.3461 

1.8764,0.6922 

2.  8146 

1.0384 

3.75281.3845 

4.6910  1.7306 

45 

30 

9367 

3502 

8733 

7004 

8100 

0506 

7467 

4008 

6834   7510 

30 

45 

9351 

3543 

8703 

7086 

8054 

0629  7405 

4172 

6757 

7715 

15 

21  0 

9336 

3584 

8672 

7167 

8007 

0751 

7343 

4335 

6679 

7918 

69  0 

15 

9320 

3624 

8640 

7249 

7960 

0873 

7280 

4498 

6600 

8122 

45 

30 

9304 

3665 

8608 

7330 

7913 

0995 

7217 

4660 

6521 

8325 

30 

45 

9288 

3706 

8576 

7411 

7864 

1177 

7152 

4822 

6440 

8528 

15 

22  0 

9272 

3746 

8544 

7492 

7816 

1238 

7087 

4984 

6359 

8730 

68  0 

15 

9255 

3786 

8511 

7573 

7766 

1359 

7022 

5146 

6277 

8932 

45 

30 

9239 

3827 

8478 

7654 

7716 

1481 

6955 

5307 

6194 

9134 

30 

45 

0.  9222 

0.3867 

1.8444 

0.  7734 

2.  7666 

1.16013.68881.5468 

4.6110 

1.  9336 

15 

23  0 

9205 

3907 

8410 

7815 

7615 

1722 

6820  5629 

6025 

9537 

67  0 

15 

9188 

3947 

8376 

7895 

7564 

1842 

6752S  5790 

5940   9737 

45 

30 

9171 

3987 

8341 

7975 

7512 

1962 

6682,  5950 

5853   9937 

30 

45 

9153 

4027 

8306 

8055 

7459 

2082 

6612!  6110 

5766  2.0137 

15 

24  0 

9135 

4067 

8271 

8135 

7406 

2202 

6542  6269 

5677   0337 

66  0 

15 

9118 

4107 

8235 

8214 

7353 

2322 

6470,  6429 

5588   0536 

45 

30 

9100 

4147 

8199 

8294 

7299 

2441  j  6398j  6588 

5498   0735 

30 

45 

9081 

4187 

8163 

8373 

7214 

2560 

6326  6746 

5407   0933 

15 

25  0 

9063 

4226 

8126  8452  7189 

2679 

6252!  6905 

5315   1131 

65  0 

15 

0.  9045  0.  4266 

1.8099  0.8531!  2.  7034 

1.2797 

3.61781.70634.5223 

2.  1328 

45 

30 

9026  4305  8052  8610  7078 

2915 

6103  72201  5129 

1526 

30 

45 

9007  43441  8014!  8689 

7021 

3033 

6028  7378  5035 

1722 

15 

26  0 

8988  4384!  7976  j  S767 

6964 

3151 

5952  7535  4940 

1919 

64  0 

15 

8969|  4423  7937i  8846 

6906 

3269 

5875!  7692  4844 

2114 

45 

30 

8949!  4462 

7899  8924 

6848 

3386 

5797  7848  4747 

2310 

30 

45 

8930  4501 

7860  9002 

8789 

3503 

5719  8004!  4649 

2505 

15 

27  0 

8910  4540  7820  9080 

6730 

3620 

5640  8160  4550 

2700 

63  0 

15 

8890  4579  7780  9157 

6671 

3736 

5561  8315  4451 

2894 

45 

30 

8870|  4617 

7740  9235 

6610 

3852 

5480  8470  4351 

3087 

30 

45 

0.88500.4656 

1.77000.9312 

2.  6550 

1.3908 

3.54001.86254.4249 

2.  3281 

15 

28  0 

8829!  4695 

7659  9389 

6488 

4084 

5318  8779  4147 

3474 

62  0 

15 

8809  4733 

7618  9466 

6427 

4200 

5236;  8933  4045 

3666 

45 

30 

8788  4772  75761  9543 

6365 

4315 

5153  9086  3941 

3858 

30 

45 

8767  4810  7535  9620 

6302 

4430 

5069  9240  3836 

4049 

15 

29  0 

8746  4848  7492  9696 

6239 

4544 

4985!  9392  3731 

4240 

61  0 

15 

8725!  4886;  7450  9772 

6175 

4659 

4900  9545 

3625 

4431 

45 

30 

8704!  4924  7407  9848 

6111 

4773 

4814  9697 

3518 

4621 

30 

45 

8682  4962  7364 

9924 

6046 

4886 

4728  9849 

3410 

4811 

15 

30  0 

8660  5000  7321 

1.0000 

5981 

5000 

4641|2.0000 

3301 

5000 

60  0 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Dep.  Lat. 

Dep. 

Lat. 

Dist.  1. 

Dist.  2 

Dist.  3. 

Dist.  4. 

Dist.  5. 

Course. 

36      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 
TABLE  3. — Traverse — Continued. 


Course. 

Dist.  1. 

Dist.  2. 

Dist.  3. 

Dist.  4. 

Dist.  5. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

3015 

0.8638 

0.5038 

1.  7277 

1.0075 

2.5915 

1.5113 

3.4553 

2.0151 

4.3192 

2.5189 

59  45 

30 

8616 

50~5 

7233 

0151 

5849 

5226  4465 

0302 

3081 

5377 

30 

45 

8594 

5113 

7188 

0226 

5782 

5339  4376 

0452 

2970 

5565 

15 

31  0 

8572 

5150 

7142 

0301 

5715 

5451  4287 

0602 

2858 

5752 

59  0 

15 

8549 

5188 

7098 

0375 

5647 

5563 

4196 

0751 

2746 

5939 

45 

30 

8526 

5225 

7053 

0450 

5579 

5675 

4106 

0900 

2632 

6125 

30 

45 

8504 

5262 

7007 

0524 

5511 

5786 

4014 

1049 

2518 

6311 

15 

32  0 

8480 

5299 

6961 

0598 

5441 

5898 

3922 

1197 

2402 

6496 

58  0 

15 

8457 

5336  6915 

0672 

5372 

6008 

3829 

1345 

2286 

6681 

45 

30 

8434 

5373  !  6868  0746 

5302 

6119  3736 

1492 

2170 

6865 

30 

45 

0.8410 

0.54101.68211.08192.5231 

1.62293.3642 

2.  1639 

4.2052 

2.  7049 

15 

33  0 

8387  5446!  6773 

0893 

5160 

6339  3547 

1786 

1934 

7232 

57  0 

15 

8363 

5483  6726 

0966 

5089 

6449  3451 

1932 

1814 

7415 

45 

30 

8339 

5519  6678 

1039 

5017 

6558  3355 

2077 

1694 

7597 

30 

45 

8315 

5556!  6629 

1111 

4944 

6667  3259 

2223 

1573 

7779 

15 

34  0 

8290 

5592;  6581 

1184 

4871 

6776  3162 

2368 

1452 

7960 

56  0 

15 

8266 

5628!  6532 

1256 

4798 

6884  3064 

2512 

1329 

8140 

45 

30 

8241 

56641  6483 

1328 

4724 

6992  2965 

2656 

1206 

8320 

30 

45 

8216 

57001  6433 

1400 

4649 

7100 

2866 

2800 

1082 

8500 

15 

35  0 

8192 

5736  6383 

1472 

4575 

7207 

2766 

2943 

0958 

8679 

55  0 

15 

0.8166 

0.57711.63331.1543 

2.  4499 

1.7314 

3.  2066 

2.  3086 

4.  0832 

2.  8857 

45 

30 

8141 

5807 

6282 

1614 

4423 

7421 

2565 

3228 

0706 

9035 

30 

45 

8116 

5842 

6231 

1685 

4347 

7527 

2463 

3370 

0579 

9212 

15 

36  0 

8090 

5878 

6180 

1756 

4271 

7634 

2361 

3511 

0451 

9389 

54  0 

15 

8064 

5913 

6129 

1826 

4193 

7739 

2258 

3652 

0322 

9565 

45 

30 

8039 

5948 

6077 

1896 

4116 

7845 

2154 

3793 

0193 

9741 

30 

45 

8013 

5983 

6025 

1966 

4038 

7950 

2050 

3933 

0063 

9916 

15 

37  0 

7986 

6018 

5973 

2036 

3959 

8054 

1945 

4073 

3.  9932 

3.0091 

53  0 

15 

7960 

6053 

5920 

2106 

3880 

8159 

1840 

4212 

9800 

0365 

45 

30 

7934 

6088 

5867 

2175 

3801 

8263 

1734 

4350 

9668 

0438 

30 

45 

0.7907 

0.  6122 

1.5814 

1.2244 

2.  3721 

1.8367 

3.  1628 

2.  4489 

3.  9534 

3.  0611 

15 

38  0 

7880 

6157 

5760 

2313 

3640 

8470 

1520 

4626 

9400 

0783 

52  0 

15 

7853 

6191 

5706i  2382 

3560 

8573 

1413 

4764 

9266 

0955 

45 

30 

7826 

6225 

5652 

2450 

3478 

8675 

1304 

4901 

9130 

1126 

30 

45 

7799 

6259 

5598 

2518 

3397 

8778 

1195 

5037 

8994 

1296 

15 

39  0 

7771 

6293 

5543 

2586 

3314 

8880 

1086 

5173 

8857 

1466 

51  0 

15 

7744 

6327 

5488 

2654 

3232 

8981 

0976 

5308 

8720 

1635 

45 

30 

7716 

6361 

5432 

2722 

3149 

9082 

0865 

5443 

8581 

1804 

30 

45 

7688 

6394 

5377 

2789 

3065 

9183 

0754 

5578 

8442 

1972 

15 

40  0 

7660 

6428 

5321 

2856 

2981 

9284 

0642 

5712 

8302 

2139 

50  0 

15 

0.  7632 

0.  6461 

I.b265 

1.2922 

2.  2897 

1.  9384 

3.  0529 

2.  5845 

3.8162 

3.  2306 

45 

30 

7604 

6494 

5208 

2989 

2812 

9483 

0416 

5978 

8020 

2472 

30 

45 

7576 

6528 

5151 

3055 

2727 

9583 

0303 

6110 

7878 

2638 

15 

41  0 

7547 

6561 

5094 

3121 

2641 

9682 

0188 

6242 

7735 

2803 

49  0 

15 

7518 

6593 

5037 

3187 

2555 

9780 

0074 

6374 

7592 

2967 

45 

30 

7490 

6626 

4979 

3252 

2469 

9879 

2.  9958 

6505 

7448 

3131 

30 

45 

7461 

6659 

4921 

3318 

2382 

9976 

9842 

6635 

7303 

3294 

15 

42  0 

7431 

6691 

4863 

3383 

2294 

2.  0074 

9726 

6765 

7157 

3457 

48  0 

15 

7402 

6724 

4804 

3447 

2207 

0171 

9609  6895 

7011   3618 

45 

30 

7373 

6756 

4746 

3512 

2118 

0268 

9491   7024 

6864   3780 

30 

45 

0.73430.6788 

1.4686 

1.3576 

2.  2030 

2.  0364 

2.93732.7152 

3.6716  3.3940 

15 

43  0 

7314!  6820 

4627 

3640 

1941 

0460 

9254!  7280 

6568   4100 

47  0 

15 

7284 

6852 

4567 

3704 

1851 

0555 

9135 

7407 

6419   4259 

45 

30 

7254 

6884 

4507 

3767 

1761 

0651 

9015 

7534 

6269 

4418 

30 

45 

7224 

6915 

4447 

3830 

1671 

0745 

8895 

7661 

6118 

4576 

15 

44  0 

7193 

6947 

4387 

3893 

1580 

0840 

8774  7786 

5967 

4733 

46  0 

15 

7163 

6978 

4326 

395G 

1489 

0934 

8652 

7912 

5815 

4890 

45 

30 

7133 

7009 

4265 

4018 

1398 

1027 

8530 

8036 

5663 

5045 

30 

45 

7102 

7040 

4204 

4080 

1306 

1120 

8407 

8161 

5509 

5201 

15 

45  0 

7071 

7071 

4142 

4142 

1213 

1213 

8284 

8284 

5355 

5355 

45  0 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

"LatT 

D^pT 

Lat. 

Dep. 

Lat. 

Course. 

Dist.  1. 

Dist.  2. 

Dist.  3. 

Dist.  4. 

Dist.  5. 

TRAVERSE. 


37 


TABLE  3. —  Traverse — Continued. 


Dist.  6. 

Dist.  7. 

Dist.  8. 

Dist.  9. 

Dist.  10. 

Course. 

Lat.  Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

0  15 

5.  9999 

0.0262 

6.9999 

0.0305 

7.9999 

0.0349 

8.9999 

0.0393 

9.9999 

0.0436 

89  45 

30 

9998 

0524 

9997 

0611 

9997 

0698 

9997 

0785 

9996 

0873 

30 

45 

9995 

0785 

9994 

0916 

9993 

1047 

9992 

1178 

9996 

1309 

15 

1  0 

9991 

1047 

9989 

1222 

9988 

1396 

9986 

1571 

9985 

1745 

89  0 

15 

9986 

1309 

9983 

1527 

9981 

1745 

9979 

1963 

9976 

2181 

45 

30 

9979 

1571 

9976 

1832 

9973 

2094 

9969 

2356 

9966 

2618 

30 

45 

9972 

1832  9967 

2138 

9963 

2443 

9958 

2748 

9953 

3054 

15 

2  0 

9963 

2094  9957 

2443 

9951 

2792 

9945 

3141 

9939 

3490 

88  0 

15 

9954 

2356!  9946 

2748 

9938 

3141 

9931 

3533 

9923 

3926 

45 

30 

9943 

2617  9933 

3053 

9924 

3490 

9914 

3926 

9905 

4362 

30 

45 

5.9931 

0.28796.9919 

0.3358 

7.9908 

0.  3838 

8.  9896 

0.4318 

9.9885 

0.  4798 

15 

3  0 

9918 

31401  9904 

3664 

9890 

4187 

9877 

4710 

9863 

5234 

87  0 

15 

9904 

3402 

9887 

3968 

9871 

4535 

9855 

5102 

9839 

5669 

45 

30 

9888 

3663 

9869 

4273 

9851 

4884 

9832 

5494 

9813 

6105 

30 

45 

9872 

3924 

9850 

4578 

9829 

5232 

9807 

5886 

9786 

6540 

15 

4  0 

9854 

4185 

9829 

4883 

9805 

5581 

9781 

6278 

9756 

6976 

86  0 

15 

9835 

4447 

9808 

5188 

9780 

5929 

9753 

6670 

9725 

7411 

45 

30 

9815 

4708 

9784 

5492 

9753 

6277 

9723 

7061 

9692 

7846 

30 

45 

9794 

4968 

9760 

5797 

9725 

66?5 

9691 

7453 

9657 

8281 

15 

5  0 

9772 

5229 

9734 

6101 

9696 

6972 

9658 

7844 

9619 

8716 

85  0 

15 

5.9748 

0.54906.9706 

0.6405 

7.9664 

0.7320 

8.  9622 

0.8235 

9.  9580 

0.9150 

45 

30 

9724 

5751 

9678 

6709 

9632 

7668 

9586 

8626 

9540 

9585 

30 

45 

9698 

6011 

9648 

7013 

9597 

8015 

9547 

9017 

9497 

1.0019 

15 

6  0 

9671 

6272 

9617 

7317 

9562 

8362 

9507 

9408 

9452 

0453 

84  0 

15 

9643 

6532 

9584 

7621 

9525 

8709 

9465 

9798 

9406 

0887 

45 

30 

9614 

6792 

9550 

7924 

9486 

9056 

9421 

1.0188 

9357 

1320 

30 

45 

9584 

7052 

9515 

8228 

9445 

9403 

9376 

0578 

9307 

1754 

15 

7  0 

9553 

7312 

9478 

8531 

9404 

9750 

9329 

0968 

9255 

2187 

83  0 

15 

9520 

7572 

9440 

8834 

9360 

1.0096 

9280 

1358 

9200 

2620 

45 

30 

9487 

7832 

9401 

9137 

9316 

0442 

9230 

1747 

9144 

3053 

30 

45 

5.9452 

0.80916.9361 

0.9440 

7.9269 

1.0788 

8.9178 

1.2137 

9.9087 

1.3485 

15 

8  0 

9416 

8350  9319 

9742 

9221 

1134 

9124 

2526 

9027 

3917 

82  0 

15 

9379 

8610!  9276 

1.0044 

9172 

1479 

9069 

2914 

8965 

4349 

45 

30 

9341 

8869  9231 

0347 

9121 

1825 

9011 

3303 

8902 

4781 

30 

45 

9302 

9127 

9185 

0649 

9069 

2170 

8953 

3691 

8836 

5212 

15 

9  0 

9261 

9386 

9138 

0950 

9015 

2515 

8892 

4079 

8769 

5643 

81  0 

15 

9220 

9645 

9090 

1252 

8960 

2859 

8830 

4467 

8700 

6074 

45 

30 

9177 

9903 

9040 

1553 

8903 

3204 

8766 

4854 

8629 

6505 

30 

45 

9133 

1.0161 

8989 

1854 

8844 

3548 

8700 

5241 

8556 

6935 

15 

10  0 

9088 

0419 

8937 

2155 

8785 

3892 

8633 

5628 

8481 

7365 

80  0 

15 

5.9042 

1.06776.8883 

1.2456 

7.8723 

1.4235 

8.  8564 

1.6015 

9.8404 

1.7794 

45 

30 

8995 

09341  8728 

2756 

8660 

4579 

8493 

6401 

8325 

8224 

30 

45 

8947 

1191]  8772 

3057 

8596 

4922 

8421 

6787 

8245 

8652 

15 

11  0 

8898 

1449 

8714 

3357 

8530 

5265 

8346 

7173 

8163 

9081 

79  0 

15 

8847 

1705 

8655 

3656  8463 

5607 

8271 

7558 

8079 

9509 

45 

30 

8795 

1962 

8595 

3956  8394 

5949 

8193 

7943 

7992 

9937 

30 

45 

8743 

2219 

8533 

4255  8324 

6291 

8114 

8328 

7905 

2.0364 

15 

12  0 

8689 

2475 

8470 

4554  8252 

6633 

8033 

8712 

7815 

0791 

78  0 

15 

8634 

2731 

8406 

4852  8178 

6974 

7951 

9096 

7723 

1218 

45 

30 

8578 

2986 

8341 

5151  !  8104 

7315 

7867 

9480 

7630 

1644 

30 

45 

5.8521 

1.3242 

6.  8274 

1.54497.8027 

1.7656 

8.  7781 

1.9863 

9.  7534 

2.2070 

15 

13  0 

8462 

3497 

8206 

5747 

7950 

7996 

7693 

2.0246 

7437 

2495 

77  0 

15 

8403 

3752 

8137 

6044 

7870 

8336 

7604 

0628 

7338 

2920 

45 

30 

8342 

4007 

8066J  6341  7790 

8676 

7513 

1010 

7237 

3345 

30 

45 

8281 

4261 

7994 

6638 

7707 

9015 

7421 

1392 

7134 

3769 

15 

14  0 

8218 

4515 

7921 

6935 

7624 

9354 

7327 

1773 

7030 

4192 

76  0 

15 

8154 

4769 

7846 

7231 

7538 

9692 

7231 

2154 

6923 

4615 

45 

30 

8089 

5023 

7770 

7527 

7452 

2.0030 

7133 

2534 

6815 

5038 

30 

45 

8023 

5276 

7693 

7822 

7364 

0368 

7034 

2914 

6705 

5460 

15 

15  0 

7956 

5529 

7615 

8117 

7274 

0706 

6933 

3294 

6593 

5882 

75  0 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Course. 

Dist.  6. 

Dist.  7. 

Dist.  8. 

Dist.  9. 

Dist.  10. 

18      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 


TABLE  3. — Traverse — Continued. 


Course. 

Dist.  6. 

Dist.  7. 

Dist.  8. 

Dist.  9. 

Disl 
Lat. 

,.  10. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat.  1  Dep. 

Lat. 

Dep. 

Dep. 

O   / 

0   / 

15  15 

5.7887 

1.  5782 

6.  7535 

1.  8412 

7.  7183  2.  1042 

8.  6831 

2.  3673  9.  6479 

2.6303 

74  45 

30 

7818 

6034 

7454 

8707 

7090 

1379 

6727 

4051  6363 

6724 

30 

45 

7747 

6286 

7372 

9001 

6996 

1715 

6621 

4430 

6246 

7144 

15 

16  0 

7676 

6538 

7288 

9295 

6901 

2051 

6514 

4807 

6126 

7564 

74  0 

15 

7603 

6790 

7203 

9588 

6804 

2386 

6404 

5185 

6005 

7983 

45 

30 

7529 

7041 

7117  9881 

6706 

2721 

6294 

5561 

5882 

8402 

30 

45 

7454 

7292 

7030  2.  0174 

6606 

3056 

6181 

5938 

5757 

8820 

15 

17  0 

7378 

7542 

6941  0466 

6504 

3390 

6067 

6313 

5630 

9237 

73  0 

15 

7301 

7792 

6851  0758 

6402 

3723 

5952 

6689 

5502 

9654 

45 

30 

7223 

8042 

6760  1049 

6297 

4056  5835 

7064 

5372  3.0071 

30 

45 

5.7144 

1.  8292 

6.  6668,2.  1341 

7.  6192 

2.  4389 

8.5716 

2.  7438 

9.5240  3.0486 

15 

18  0 

7063 

8541 

6574  1631 

6085 

4721 

5595 

7812 

5106   0902 

72  0 

15 

6982 

8790 

6479 

1921 

5976 

5053 

5473 

8185 

4970 

1316 

45 

30 

6899 

9038 

6383 

2211 

5866 

5384 

5349 

8557 

4832   1730 

30 

45 

6816 

9286 

6285  2501 

5754 

5715 

5224 

8930 

4693   2144 

15 

19  0 

6731 

9534 

6186  2790 

5641 

6045 

5097 

9301 

4552i   2557 

71  0 

15 

6645  9781 

6086  3078 

5527 

6375 

4968 

9672 

4409!   2969 

45 

30 

65582.0028 

5985  3366 

5411 

6705 

4838 

3.  0043 

4264   3381 

30 

45 

6471  0275 

5882  3654 

5294 

7033 

4706 

0413 

41  18'   3792 

15 

20  0 

6382  0521 

5778  3941 

5175 

7362  4572 

0782 

3969   4202 

70  0 

15 

5.62912.0767 

6.  5673  2.  4228 

7.  5055 

2.  768918.  4437 

3.11519.3819  3.4612 

,  45 

30 

6200  1012 

5567  4515 

4934 

8017 

4300 

1519  3667!   5021 

30 

45 

6108 

1257 

5459 

4800 

4811 

8343 

4162 

1886 

3514   5429 

15 

21  0 

6015 

1502 

5351 

5086 

4686 

8669 

4022 

2253 

3358   5837 

69  0 

15 

5920 

1746 

5241 

5371 

4561 

8995 

3881 

2619 

3201   6244 

45 

30 

5825 

1990 

5129 

5655 

4433 

9320 

3738 

2985 

3042   6650 

30 

45 

5729 

2233 

5017 

5939 

4305 

9645 

3593 

3350 

2881   7056 

15 

22  0 

5631 

2476 

4903 

6222 

4175 

9969 

3447 

3715 

2718   7461 

68  0 

15 

5532 

2719 

4788 

6505 

4043 

3.  0292 

3299 

4078 

2554   7855 

45 

30 

5433 

2961 

4672 

6788 

3910 

0615 

3149 

4442 

2388|   8268 

30 

45 

5.5332 

2.  3203 

6.  4554 

2.  7070 

7.3776 

3.  0937 

8.2998 

3.  4804 

9.2220  3.8671 

15 

23  0 

5230 

3414 

4435 

7351 

3640 

1258 

2845 

5166 

2050   9073 

67  0 

15 

5127 

3685 

4315 

7632 

3503 

1580 

2691 

5527 

1879   9474 

45 

30 

5024 

3925 

4194 

7912 

3365 

1900 

2535 

5887 

1706   9875 

30 

45 

4919 

4165 

4072 

8192 

3225 

2220 

2378 

6247 

1531  4.0275 

15 

24  0 

4813 

4404 

3948 

8472 

3084 

2539 

2219 

6606 

1355   0674 

66  0 

15 

4706 

4643 

3823 

8750 

2941 

2858 

2059 

6965 

1176   1072 

45 

30 

4598 

4882 

3697 

9029 

2797 

3175 

1897 

7322 

0996   1469 

30 

45 

4489 

5120 

3570 

9306 

2651 

3493 

1733 

7679 

0814   1866 

15 

25  0 

4378 

5357 

3442 

9583 

2505 

3809 

1568 

8036 

0631   2262 

65  0 

15 

5.4267 

2.  5594 

6.  3312  2.  9800 

7.  2356 

3.  4125 

8.  1401 

3.83919.0446  4.2657 

45 

30 

4155 

5831 

3181!3.0136 

2207 

4441 

1233 

8746  0259   3051 

30 

45 

4042 

6067 

3049 

0411 

2056 

4756 

1063 

9100  0070   3445 

15 

26  0 

3928 

6302 

2916 

0686 

1904 

5070 

0891 

94538.9879   3837 

64  0 

15 

3812 

6537 

2781 

0960 

1750 

5383 

0719 

9806 

9687   4229 

45 

30 

3696 

6772 

2645 

1234 

1595 

5696 

0644 

4.  0158 

9493   4620 

30 

45 

3579 

7006 

2509 

1507 

1438 

6008 

0368 

0509 

9298 

5010 

15 

27  0 

34601  7239 

2370 

1779 

1281 

6319 

0191 

0859 

9101 

5399 

63  0 

15 

3341 

7472 

2231 

2051 

1121 

6630 

0012 

1209 

8902 

5787 

45 

30 

3221 

7705 

2091  2322 

0961 

6940 

7.9831 

1557 

8701 

6175 

30 

45 

5.30992.7937 

6.  1949  3.  2593 

7.  0799 

3.  7249 

7.  9649 

4.  1905 

8.  8499 

4.6561 

15 

28  0 

2977  8168 

1806  2863 

0636 

7558 

9465 

2252 

8295 

6947 

62  0 

15 

28531  8399 

1662'  3132 

0471 

7866 

9280 

2599 

8089 

7332 

45 

30 

2729 

8630 

1517 

3401 

0305 

8173 

9094J  2944 

7882 

7716 

30 

45 

2604 

8859 

1371 

3669 

0138 

8479 

8905  3289 

7673 

8099 

15 

29  0 

2477 

9089 

1223 

3937 

6.  9970 

8785 

8716 

3633 

7462 

8481 

61  0 

15 

2350 

9317 

1075 

4203 

9800 

9090 

8525 

3976 

7250 

8862 

45 

30 

2221 

9545 

0925 

4470 

9628 

9394 

8332 

4318 

7036 

9242 

30 

45 

2092 

9773 

0774 

4735 

9456 

9697 

8138 

4659 

6820 

9622 

15 

30  0 

1962 

3.0000 

0622 

5000 

9282 

4.0000 

7942 

5000 

6603 

5.0000 

60  0 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Dep.  |  Lat. 

Course. 

Dist.  6. 

Dist.  7. 

Dist.  8. 

Dist.  9. 

Dist.  10. 

TRAVERSE, 


39 


TABLE  3. —  Traverse — Continued. 


Dist.  6. 

Dist.  7. 

Dist.  8. 

Dist.  9. 

Dist.  10. 

Course. 

Lat.  i  Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat.  Dep. 

Lat.  Dep. 

30  15 

5.  1830  3.  0226 

6.  0468  3.  5264 

6.  9107 

4.0302 

7.  7745  4.  5340 

8.6384  5.0377 

59  45 

30 

1698 

0452 

0314  5528 

8930 

0603 

7547|  5678 

6163   0754 

30 

45 

1564 

0678 

0158 

5791 

8753 

0903 

73471  6016 

5941   1129 

15 

31  0 

1430 

0902 

0002 

6053 

8573 

1203 

7145  6353 

5717 

1504 

59  0 

15 

1295 

1126 

5.  9844 

6314 

8393 

1502 

6942|  6690 

5491 

1877 

45 

30 

1158 

1350 

9685 

6575 

8211 

1800 

6738J  7025 

5264 

2250 

30 

45 

1021 

1573 

9525 

6835 

8028 

2097 

6532  7359 

5035 

2621 

15 

32  0 

0883 

1795 

9363 

7094 

7844 

2394 

6324  7693 

48)5 

2992 

58  0 

15 

0744 

2017 

9201 

7353 

7658 

2689 

6116  8025 

4573 

3361 

45 

30 

0603 

2238 

9037 

7611 

7471 

2984 

5905  8357 

4339 

3730 

30 

45 

5.  0462 

3.  2458 

5.8873 

3.  7868 

6.  7283 

4.  3278 

7.56944.8688 

8.  4104 

5.  4097 

15 

33  0 

0320 

2678 

8707 

8125 

7094 

3571 

54801  9018 

3867 

4464 

57  0 

15 

0177 

2898 

8540 

8381 

6903 

3863 

5266  9346 

3629 

4829 

45 

30 

0033 

3116 

8372 

8636 

6711 

4155 

5050!  9674 

3389 

5194 

30 

45 

4.9888 

3334 

8203 

8890 

6518 

4446 

4832  5.  0001 

3147 

5557 

15 

34  0 

9742 

3552 

8033 

9144 

6323 

4735 

4613!  0327 

2904 

5919 

56  0 

15 

9595 

3768 

7861 

9396 

6127 

5024 

4393 

0652 

2659 

6280 

45 

30 

9448 

3984 

7689 

9848 

5930 

5312 

4171 

0977 

2413 

6641 

30 

45 

9299 

4200 

7515 

9900 

5732 

5600 

3948 

1300 

2165 

7000 

15 

35  0 

9149 

4415 

7341 

4.  0150 

5532 

5880 

3724 

1622 

1915 

7358 

55  0 

15 

4.  8998 

3.4629 

5.  7165 

4.0400 

6.  5331 

4.  6172 

7.  3498 

5.  1943 

8.  1664 

5.  7715 

45 

30 

8847 

4842 

6988 

0649 

5129 

6456 

3270 

2263 

1412 

8070 

30 

45 

8694 

5055 

6810 

0897 

4926 

6740 

3042 

2582 

1157 

8425 

15 

36  0 

8541 

5267 

6631 

1145 

4721 

7023 

2812 

2901 

0902 

8779 

54  0 

15 

8387 

5479 

6451 

1392 

4516 

7305 

2580 

3218 

0644 

9131 

45 

30 

8231 

5689 

6270 

1638 

4309 

758(5 

2347 

3534 

0386 

9482 

30 

45 

8075 

5899 

6088 

1883 

4100 

786G 

2113 

3849 

0125 

9832 

15 

37  0 

7918 

6109 

5904 

2127 

3891 

8145 

1877 

4163 

7.  9864 

6.  0182 

53  0 

15 

7760 

6318 

5720 

2371 

3680 

8424 

1640 

4476 

9600 

0529 

45 

30 

7601 

6526 

5535 

2613 

3468 

8701 

1402 

4789 

9335 

0876 

30 

45 

4.  7441 

3.  6733 

5.  5348 

4.  2855 

6.  3255 

4.8977 

7.  1162 

5.5100 

7.  9069 

6.  1222 

15 

38  0 

7281 

6940 

5161 

3096 

3041 

9253 

0921 

5410 

8801 

1566 

52  0 

15 

7119 

7146 

4972 

3337 

2825 

9528 

0679 

5718 

8532 

1909 

45 

30 

6956 

7351 

4783 

3576 

2609 

9801 

0435 

6026 

8261 

2251 

30 

45 

6793 

7555 

4592 

3815 

2391 

5.  0074 

0190 

6333 

7988 

2592 

15 

39  0 

6629 

7759 

4400 

4052 

2172 

0346 

6.  9943 

6639 

7715 

2932 

51  0 

15 

6464 

7962 

4207 

4289 

1951 

0616 

9696 

6943 

7439 

3271 

45 

30 

6297 

8165 

4014 

4525 

1730 

0886 

9446 

7247 

7162 

3608 

30 

45 

6131 

8366 

3819 

4761 

1507 

1155 

9196 

7550 

6884 

3944 

15 

40  0 

5963 

8567 

3623 

4995 

1284 

1423 

8944 

7851 

6604 

4279 

50  0 

15 

4.  5794 

3.  8767 

5.  3426  4.  5229 

6.  1059 

5.  1690 

6.  8691 

5.8151 

7.  6323 

6.  4612 

45 

30 

5624 

8967 

3228'  5461 

0832 

1956 

8437 

8450 

6041 

4945 

30 

45 

5454 

9166 

3030J  5693 

0605 

2221 

8181 

8748 

5756 

52"6 

15 

41  0 

5283 

9364 

2830  5924 

0377 

2485 

7924 

9045 

5471 

5606 

49  0 

15 

5110 

9561 

2629:  6154 

0147 

2748 

7666 

9341 

5184 

5935 

45 

30 

4937 

9757 

2427 

6383 

5.  9916 

3010 

7406 

9636 

4896 

6262 

30 

45 

4763 

S953 

2224 

6612 

9685 

3271 

7145 

9929 

4606 

6588 

15 

42  0 

4589 

4.  0148 

2020 

6839 

9452 

3530 

6883 

6.0222 

4314 

6913 

48  0 

15 

4413 

0342 

18151  7066 

9217 

3789 

6620 

0513 

4022 

7237 

45 

30 

4237 

0535 

1609  7291 

8982 

4047 

6355 

0803 

3728 

75o9 

30 

45 

4.  4059 

4.0728 

5.  1403  4.  7516 

5.  874(5 

5.  4304 

<i.  60S!) 

6.  1092 

7.  3432 

6.7880 

15 

43  0 

3881 

0920 

1195|  7740 

8508 

4560 

5822 

1380 

3135 

8200 

47  0 

15 

3702 

1111 

0986*  7963 

8270 

4815 

5553 

1666 

2837 

8518 

45 

30 

3522 

1301 

0776  8185 

8030 

5068 

5284 

1952 

2537 

8835 

30 

45 

3342 

1491 

0565  8406 

7789 

5321 

5013 

2236 

2236 

9151 

15 

44  0 

3160 

1680 

0354  8626 

7547 

5573 

4741 

2519 

1934 

9466 

46  0 

15 

2978 

1867 

0141  8845 

7304 

5823 

4467 

2801 

1630 

9779 

45 

30 

2795 

2055 

4.  9928  9064 

7060 

6073 

4193 

3082 

1325 

7.0091 

30 

45 

2611 

2241 

97131  9281 

6815 

6321 

3917 

3361 

1019 

0401 

15 

45  0 

2426 

2426 

9497 

9497 

6569 

6569 

3640 

3640 

0711 

0711 

45  0 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Dep. 

Lat. 

Dist,  6. 

Dist.  7. 

Dist.  8. 

Dist.  9. 

Dist.  10. 

Course. 

40      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 


TABLE  4. — Condensed  traverse  table  for  cruising. 


De- 
grees. 

Latitude. 

Departure. 

De- 
grees. 

Latitude. 

Departure. 

0 

1.000 

0.000 

90 

23 

0.920 

0.391 

67 

1 

1.000 

.017 

89 

24 

.913 

.497 

66 

2 

.999 

.035 

88 

25 

.906 

.423 

65 

3 

.999 

.052 

87 

26 

.899 

.438 

64 

4 

.998 

.070 

86 

27 

.891 

.454 

63 

5 

.996 

.087 

85 

28 

.883 

.470 

62 

6 

.995 

.104 

84 

29 

.875 

.485 

61 

7 

.992 

.122 

83 

30 

.866 

.500 

60 

8 

.990 

.139 

82 

31 

.857 

.515 

59 

9 

.988 

.156 

81 

32 

.848 

.530 

58 

10 

.985 

.174 

80 

33 

.839 

.545 

57 

'  11 

.982 

.191 

79 

34 

.829 

.559 

56 

12 

.978 

.208 

78 

35 

.819 

.574 

55 

13 

.974 

.225 

77 

36 

.809 

.588 

54 

14 

.970 

.242 

76 

37 

.799 

.602 

53 

15 

.966 

.259 

75 

38 

.788 

.616 

52 

16 

.961 

.276 

74 

39 

.777 

.629 

51 

17 

.956 

.292 

73 

40 

.766 

.643 

50 

18 

.951 

.309 

72 

41 

.755 

.656 

49 

19 

.946 

.326 

71 

42 

.743 

.669 

48 

20 

.940 

.342 

70 

43 

.731 

.682 

47 

21 

.934 

.358 

69 

44 

.719 

.695 

46 

22 

.927 

.375 

68 

45 

.707 

.707 

45 

Departure. 

Latitude. 

De- 
grees. 

Departure. 

Latitude. 

De- 
grees. 

TABLE  5. — Surface  measuring  on  slopes. 

[Increase  of  distance  to  be  added  to  one  66'  chain  of  surface  measurement  to  give  one 
chain  of  horizontal  measurement.    Approximate;  for  use  in  cruising.] 


Slope. 

Grade. 

Equiva- 
lent verti- 
cal angle. 

Increase  of 
distance 
per  66' 
chain  (ex- 
secant).! 

Level 

Per  cent. 

0 

Links. 

Gentle  

\            5 
\           10 

3.0 
5.5 

0.1 
.5 

Moderate  

1           15 
f           20 

8.5 
11.5 

1.1 

2.0 

Steep 

\            30 

40 
50 

22.0 
26.5 

7.8 
11.7 

Very  steep 

60 

70 
80 

31.0 
35.0 
38.5 

16.6 
22.1 

28.0 

90 
100 

42.0 
45.0 

34.6 
41.4 

The  per  cent  of  grade  is  determined  by  grademeter  or  hypsometer. 
Vertical  angles  are  read  by  clinometer,  Abney  level,  or  transit, 
i  The  exsecant  is  a  ratio  of  links  per  100  links  (=1  chain),  and  therefore  the  figures 
In  this  column  also  show  feet  per  100  feet,  or  yards  per  100  yards,  etc. 


BLAZES  AND  MARKS  ON  TREES.  41 

BLAZES   AND   MARKS   ON   TREES. 

Trees  should  never  be  blazed  nor  marked  upon  random 
or  trial  lines  nor  upon  other  preliminary  or  temporary 
surveys,  where  they  may  be  misleading  in  the  future. 

A  survey  line  is  Hazed  in  order  that  it  may  be  located 
or  retraced  between  corners  which  are  at  each  end  of 
the  line.  Corners  and  intersections  are  witnessed  by 
marks.  Thus  the  ax  scars  used  in  surveying  may  be 
either  blazes  or  marks,  one  term  being  applied  to  a 
line  and  the  other  to  a  point.  In  some  books  on 
surveying  these  terms  have  been  used  interchangeably 
or  carelessly,  but  it  is  better  to  make  the  distinction  in 
the  Forest  Service,  where  surveying  is  done  for  so 
many  different  purposes. 

A  survey  line  is  Hazed  in  the  following  manner: 
Trees  which  are  on  the  line  are  blazed  fore  and  back, 
meaning  that  the  surveyor  took  a  foresight  when  run- 
ning toward  the  tree  and  a  backsight  when  running 
away  from  it,  on  the  same  straight  line.  Such  a  tree  is 
called  a  line  tree  and  is  spoken  of  as  being  line-blazed. 
Trees  standing  near  the  line,  within  50  links  on  either 
side,  are  blazed  on  two  sides  quartering  toward  the  line. 

Blazes  for  roads  need  not  be  permanent  because  the 
subsequent  construction  of  the  highway  fixes  the  line. 
Property  lines  should  be  permanently  blazed — that  is, 
through  the  bark  to  the  wood,  leaving  a  scar  which 
may  be  recognized  or  found  as  long  as  the  tree  stands. 
Blazes  should  be  the  width  of  an  ax  blade,  about  6 
inches  long,  and  placed  breast  high.  When  it  is 
probable  that  the  blazes  will  be  used  when  there  is 
deep  snow  upon  the  ground,  they  should  be  placed 
high  enough  to  be  seen,  or  the  trees  may  be  given  a 


42 

second  blazing  at  a  higher  point  after  the  deep  snow 
renders  this  convenient. 

It  is  often  desirable,  as  in  the  case  of  trails,  that 
Forest  Service  blazes  should  be  distinguished  from 
land  office  blazes  or  from  private  surveys,  and,  there- 
fore, a  distinctive  blaze  has  been  adopted  for  the 
Forest  Service.  This  is  the  width  of  an  ax  blade, 
about  6  inches  long,  with  a  horizontal  notch  at  the 
top  of  the  scar. 

The  Forest  Service  has  also  adopted  a  distinctive 
mark  to  indicate  the  intersection  of  one  of  its  lines 
with  a  land  office  line  and  to  show  the  approximate 
distance  to  the  nearest  land  office  corner.  Thus, 
when  a  road  or  trail  crosses  a  section  line  a  tree  may 
be  marked  in  such  a  manner  that  any  Forest  officer 
may  recognize  it,  and  will  know  the  direction  and 
approximate  distance  to  the  nearest  section  or  quarter- 
section  corner.  This  mark  is  made  in  the  following 
manner:  A  tree  near  the  point  of  intersection  is 
barked  to  the  wood,  about  8  by  10  inches,  on  the 
side  facing  the  corner.  A  letter  C  with  horizontal 
crossbars  is  then  scribed  upon  the  scar.  A  horizontal 
bar  will  indicate  that  the  distance  to  the  corner  is 
about  10  chains,  and  each  half  bar  will  indicate  a 
distance  of  about  5  chains.  For  example,  the  inter- 
section marks  may  read  as  follows: 

€  €  €  € 

About     5         About       10        A  b  o  u  t    15         A  b  o  u  t    20        A  b  o  u  t    25 
chains  to  chains   to  chains   to  chains   to  chains   to 

corner.  corner.  corner.  corner.  corner. 


BLAZES  AND  MARKS  ON  TREES.  43 

It  will  sometimes  happen  that  an  intersection  tree 
can  not  be  marked  facing  the  corner  and  at  the  same 
time  have  the  mark  visible  from  the  .trail  or  road.  In 
such  cases  the  mark  will  face  the  corner  and  an  X  will 
be  cut,  through  the  bark,  on  the  side  toward  the  high- 
way. The  letter  X  is  a  recognized  symbol,  indicating 
the  crossing  of  lines  or  to  indicate  that  a  trail  crosses  a 
stream  at  this  point.  It  is  often  useful  in  the  latter 
case  when  there  is  snow  on  the  ground,  as  it  shows  that 
the  stream  must  be  forded,  and  that  the  trail  will  be 
found  on  the  other  side.  It  will,  therefore,  be  used  for 
both  purposes  mentioned,  and  its  meaning  will  never  be 
misunderstood.  The  letter  y  is  often  used  to  indicate 
that  the  trail  forks  at  this  point,  and  is  useful  when 
there  is  snow  upon  the  ground. 

It  will  frequently  happen  that  a  land-office  corner 
will  be  accidentally  found,  and  the  distance  from  it  to 
the  point  of  intersection  will  be  immediately  deter- 
mined by  pacing.  This  is  sufficiently  accurate  to  war- 
rant the  marking  of  an  intersection  witness  tree,  as 
stated  above,  as  the  distance  is  only  presumed  to  be 
approximate.  Whether  the  line  is  paced  or  measured, 
the  ranger  will  make  a  record  in  his  notebook,  describ- 
ing the  land-office  corner  and  the  distance  to  the  inter- 
section, and  the  marks  which  he  placed  at  that  point. 
The  following  is  a  specimen  of  such  a  record : 

SPECIMEN    RECORD. 

October  4,  1912,  10  a.  m.  I  found  the  quarter-corner  between 
sections  15  and  16,  T.  8  N.,  R.  21  W.  Both  witness  trees  were 
standing,  but  the  stake  had  fallen  over.  The  rotted  point  was 
found  in  the  ground  and  I  reset  the  stake  above  it,  placing  a  mound 
of  stones  about  it  to  hold  it  in  position.  From  this  corner  I  paced 
south,  following  the  original  blazes,  23  chains,  to  the  intersection 


44      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

of  the  new  Forest  Service  trail  between  Wild  Cat  Ranger  Station 
and  Alta  Lookout  Point.  Established  for  witness  red  fir  20  inches 
in  diameter,  on  north  side  of  trail,  40  links  distant  from  intersection, 
marked  €1  on  north  side  and  X  on  south  side. 

October  4,  6  p.  m.  Made  a  record  of  the  above  information  on 
the  atlas  sheet. 

JOHN  R.  UNDERWOOD, 

Ranger. 

It  is  important  that  any  geographic  information 
which  may  be  used  to  correct  the  atlas  sheets,  and 
thus  lead  to  the  preparation  of  accurate  forest  maps, 
should  be  placed  upon  the  sheets  which  are  kept  for 
that  purpose  by  each  forest  officer.  All  of  such  cor- 
rections or  additional  data  should  be  transmitted  to 
the  supervisor  as  he  may  require  them,  but  certainly 
in  ample  time  for  him  to  include  them  in  the  corrected 
folio  which  he  sends  to  the  Forester  on  February  1  of 
each  year. 

Other  marks  used  by  the  Forest  Service  are  described 
under  "Ranger  station  surveys"  and  "Forest  home- 
stead surveys.'' 

FIELD   NOTES. 

Notes  of  survey  should  show  exactly  what  was  done 
in  the  field,  including  the  errors  of  courses  or  measure- 
ments. In  resurveying  lines,  it  is  no  reflection  on  the 
survey  party  if  it  does  not  "check  up"  exactly,  but  it 
is  rather  expected  that  a  trial  or  "random  line"  will 
not  strike  a  corner  nor  the  measurement  prove  exactly 
as  "returned"  by  the  original  surveyor.  It  is  im- 
portant, however,  to  know  what  the  error  or  difference 
is  discovered  to  be. 

When  a  notebook  contains  the  field  notes  of  only  one 
survey,  the  purpose  of  which  the  survey  was  made 
should  be  plainly  marked  on  the  cover  as  well  as  on 


FIELD  NOTES.  45 

the  first  page.  If  it  contains  the  notes  of  more  than 
one  survey,  the  title  of  a  survey  should  be  written  at 
the  top  of  each  page,  and  the  book  should  be  indexed 
on  the  first  page.  Each  book  should  be  numbered  and 
paged.  When  the  notes  for  a  survey  do  not  follow  in 
regular  order  in  a  notebook  be  sure  to  refer  to  the  page 
where  the  continuation  can  bo  found  and  at  that  point 
refer  back  by  page  number  to  the  former  notes. 

It  is  a  good  plan  to  make  numerous  explanatory 
sketches  on  the  right-hand  pages  of  the  notebooks,  leav- 
ing nothing  to  the  memory,  and  particularly  the  direc- 
tion of  the  flow  of  streams  should  be  shown  by  arrows. 
If  the  surveyor  will  always  imagine  that  he  might  stop 
work  at  any  moment,  and  some  one  else  may  be  obliged 
to  continue  the  survey,  and  will  keep  his  notes  so  clearly 
that  this  would  be  easy,  then  they  are  apt  to  be  a  re- 
iable  record.  Never  erase  notes — cross  them  out  and 
mark  them  "abandoned." 

Field  notes  should  never  be  crowded  into  a  notebook 
or  be  written  as  a  continuous  recital,  but  should  be 
tabulated  clearly  that  they  may  be  readily  platted  by 
any  surveyor  or  draftsman.  A  good  form  for  keeping 
notes  is  here  shown. 

SPECIMEN    NOTES. 

.  National  Forest. 


Resurvey  of  east  boundary  of  sec.  24,  T.  19  N.,  R.  14  E. 

June  16,  1912. 
Weather  clear. 

I   corrected  both   aneroids  at   the   benchmark   at  ....  which 
has  an  elevation  of  ....  ft. 

Made  camp  5.30  p.  m.     Sec.  24,  T.  19  N.,  R.  14  E. 
7  p.  m.  Camp  barometer  reads  4,850/. 
Field  barometer  reads  4,860'. 

At  9  p.  m.  observed  Polaris  and  find  the  variation  at  camp  to 
be  19°  east. 


46      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

June  17,  1912. 
Weather  clear. 

7  a.  m.  Camp  barometer  4,850/. 
Field  barometer  4,860'. 
Resurvey  of  east  boundary  of  sec.  24,  T.   19  N.,  R.   14  E.,  in 

the National   Forest.     The  original  survey  was  made  in 

1872,  with  variation  18^°  east.     Allowing  for  the  reported  increase, 
the  variation  should  be  about  19°  05X.  Elev. 

From  the  southeast  corner  of  sec.  24 4,  780' 

Ran  north,  var.  19°  east. 

10.  00  ch.  near  36"  yellow  pine 4,  720' 

20.  00         in  thicket  of  firs 4,  680' 

24.  50        creek,  4  links  wide,  flows  SW 4,  660' 

30.  00        at  foot  of  steep  slope 4,  740' 

40.  00        on  steep  sidehill,  SE 4,  920' 

40.  23  to  a  point  15  links  west  of  £  corner  on  east  side 
sec.  24. 

On  this  line  the  original  blazes  were 
almost  obliterated,  and  I  made  new 
blazes. 

From  the  |  corner  on  east  side  of  sec.  24. 
Ran  north,  var.  19°  east. 

10.  00  ch.  enter  burned  area 5,  050' 

13.  60        top  of  hill  NE.  and  SW 5, 120' 

From  this  point  I  take  vertical  angles  on  some  high  points 
in  unsurveyed  T.  19  N.,  R.  15  E.,  as  follows:  Elev. . 

N.  24J  E.  3  miles,  vertical  angle  1$° 5,  545X 

N.  37£  E.  2i  miles,  vertical  angle  i° 5, 179' 

N.  89°  E.  ?  miles,  vertical  angle  1|° 

S.  43^  E.  4  miles,  vertical  angle  1° 5,  503' 

S.  10°  E.  3i  miles,  vertical  angle  |° 5,  355' 

thence  continue  north. 

20. 00        heavy  litter 5,  075' 

27. 30        leave  burn 

30. 00        in  good  reproduction  yellow  pine 4,  900' 

39.  85  to  a  point  20  links  east  of  NE.  cor.  of  sec.  24.  Wit- 
ness trees  standing,  but  stake  almost  destroyed. 
Set  new  stake  with  the  proper  marks  and 

U.  S.  F.  S.  on  SW.  side 4,  850' 

etc.,  etc. 

7  p.  m.  Camp  barometer,  4,870'. 
Field  barometer,  4,880'. 


FIELD   NOTES. 
ROAD,    STREAM,    OR    SUMMIT 

The  method  of  keeping  meander  notes  tfiiTeTs^  from 
the  above.  Each  course  begins  a  new  tally,  and  any 
intermediate  distances  are  entered  in  a  third  column. 
The  second  column  may  then  be  added  to  determine 
the  total  distance  surveyed,  viz: 

National  Forest. 

Meanders  in  unsurveyed  T.  19  N.,  R.  15  E. 

June  18,  1912. 
Weather  cloudy. 
7  a.  m.  Camp  barometer,  4,880'. 
Field  barometer,  4,890'. 
From  a  point  13.60  ch.  north  of  J  cor.  on  the  east  side  of 

sec.  24. 
Ran  along  summit,  var.  19°  east. 

N.  24    E.    9.00  ch.  at  6.00  leave  burn 5,200' 

N.  39i  E.  17.50        at  3.00  trail  N.  and  S 5,125' 

N.  48i  E.  11.20         5, 175' 

S.  86    E.  14.60        highest  point  on  summit 5,320' 

At  this  point  the  summit  divides;  one  branch  bear- 
ing SE.  and  the  other  SW. 
Continuing  the  meanders: 
Ran  down  gulch,  between  the  two  divides. 
Var.  19°  east. 

N.  89    E.  18.00  ch.  spring 5, 150/ 

N.  75    E.  15.00        meadow,  2  acres 5,025' 

S.  83    E.    4.00        falls,  10  feet 4,975' 

N.  80    E.  22.20        at  18.00  small  tributary  from  the  south  . .   4,  900' 
N.  86    E.    9.00        at  2.30  the  notice  of  the  Morning  Star 
mining  claim  bears  S.    1.50;  at  3.40 

mining  cabin 4, 875 

etc.,  etc. 


48      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 


TABLE  6. — Difference  of  altitude  between  the  "station"  occupied  by  the 
surveyor,  of  which  the  altitude  is  known,  and  a  higher  distant  object 
whose  altitude  is  desired. 

[Difference  of  altitude  in  feet— add  to  station  altitude.] 


Verti- 
cal 
angle 
above 
a  level 
line. 

Distance  to  object,  in  miles. 
• 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

0°00' 

5 

7 

10 

14 

19 

25 

33 

41 

51 

62 

15 

28 

53 

79 

106 

134 

163 

194 

225 

258 

292 

30 

51 

99 

148 

198 

249 

301 

356 

410 

466 

523 

45 

74 

145 

217 

290 

365 

440 

517 

594 

673 

753 

1°00' 

97 

191 

286 

383 

480 

578 

678 

778 

880 

984 

15 

120 

237 

356 

475 

595 

716 

839 

963 

1,088 

1,214 

30 

143 

283 

425 

567 

710 

855 

1,001 

1,147 

1,295 

1,445 

45 

166 

330 

494 

659 

826 

993 

1,162 

1,332 

1,503 

1,675 

2°00' 

189 

376 

563 

752 

941 

,131 

1,324 

1,516 

1,710 

1,906 

15 

212 

422 

632 

844 

1,056 

,270 

1,485 

1,701 

1,918 

2,137 

30 

235 

468 

702 

936 

1,172 

,408 

1,647 

1,885 

2,126 

2,367 

45 

259 

514 

771 

1,028 

1,287 

,547 

1,808 

2,070 

2,334 

2,598 

3°00' 

282 

560 

840 

1,121 

1,403 

,685 

1,970 

2,255 

2,541 

2,829 

15 

305 

607 

909 

1,213 

1,518 

,824 

2,132 

2,440 

2,749 

3,060 

30 

S28 

653 

979 

1,306 

1,634 

1,963 

2,294 

2,625 

2,957 

3,291 

45 

351 

699 

1,048 

1,398 

1,749 

2,101 

2,  455 

2,810 

3,166 

3,523 

4°00' 

374 

745 

1,118 

1,491 

1,865 

2,240 

2.  617 

2,995 

3,374 

3,754 

15 

397 

792 

1,187 

1,583 

1,981 

2,379 

2,780 

3,180 

3,582 

3,986 

30 

420 

838 

1,257 

1,676 

2,097 

2,518 

2,942 

3,365 

3,791 

4,217 

45 

444 

884 

1,326 

1,769 

2,213 

2,657 

3,104 

3,551 

4,000 

4,449 

5°00' 

467 

.  931 

1,396 

1,862 

2,329 

2,797 

3,267 

3,737 

4,208 

4,681 

15 

490 

977 

1,466 

1,955 

2,445 

2,936 

3,429 

3,922 

4,418 

4,914 

30 

513 

1,024 

1,535 

2,048 

2,561 

3,075 

3,592 

4,108 

4,627 

5,146 

45 

537 

1,070 

1,605 

2,141 

2,677 

3,215 

3,755 

4,294 

4,836 

5,379 

6°00' 

560 

1,117 

1,675 

2,234 

2,794 

3,355 

3,918 

4,481 

5,046 

5,612 

15 

583 

1,164 

1,745 

2,327 

2,910 

3,  495 

,081 

4,667 

5,255 

5,845 

30 

607 

1,210 

1,815 

2,420 

3,027 

3,634 

,244 

4,854 

5,465 

6,078 

45 

630 

1,257 

1,885 

2,514 

3,144 

3,775 

,407 

5,040 

5,675 

6,311 

7°00' 

653 

1,304 

1,955 

2,607 

3,261 

3,915 

,571 

5,227 

5,886 

6,545 

15 

677 

1,350 

2,025 

2,701 

3,378 

4,  055 

,735 

5,415 

6,096 

6,779 

30 

700 

1,397 

2,095 

2,795 

3,595 

4,196 

4,899 

5,602 

6,307 

7,013 

45 

724 

1,444 

2,166 

2,888 

3,612 

4,337 

5,063 

5,790 

6,518 

7,248 

8°00' 

747 

1,491 

2,236 

2,982 

3,729 

4,477 

5,227 

5,977 

6,729 

7,483 

15 

771 

1,538 

2,307 

3,076 

3,847 

4,618 

5,392 

6,166 

6,941 

7,718 

30 

794 

1,585 

2,377 

3,170 

3,964 

4,760 

5,557 

6,354 

7,153 

7,953 

45 

818 

1,632 

2,448 

3,265 

4,082 

4,901 

5,722 

6,542 

7,365 

8,189 

DIFFERENCE   OF   ALTITtTDE. 


49 


TABLE  6. — Difference  of  altitude  between  the  "station"  occupied  by  the 
surveyor,  of  which  the  altitude  is  known,  and  a  higher  distant  object 
whose  altitude  is  desired — Continued. 

[Difference  of  altitude  in  feet — add  to  station  altitude.] 


Verti- 
cal 
angle 
above 
a  level 
line. 

Distance  to  object,  in  miles. 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

9°00' 
15 
30 
45 

10°00' 
15 
30 
45 

11°00' 
15 
30 
45 

12°00' 
15 
30 
45 

13°00' 
15 
30 
45 

14W 
15 
30 
45 

15°00' 
15 
30 
45 

841 
865 
889 
912 

936 

960 
984 
1,007 

,031 
,055 
,079 
,103 

,127 
,151 
,176 
,200 

,224 

,248 
,273 
,297 

,321 
,346 
,371 
,395 

,420 
,444 
,469 
,494 

1,680 
1,727 
1,774 
1,821 

1,869 
1,917 
1,964 
2,012 

2,060 
2,108 
2,155 
2,204 

2,252 
2,300 
2,348 
2,397 

2,445 
2,494 
2,542 
2,591 

2,640 
2,689 
2,738 

2,787 

2,837 
2,886 
2.935 
2.985 

2,519 
2,590 
2,661 
2,732 

2,803 
2,874 
2,946 
3,017 

3,089 
3,161 
3,233 
3,305 

3,377 
3,449 
3,522 
3,594 

3,667 
3,740 
3,813 
3,886 

3,959 
4,033 
4,107 
4,180 

4,254 
4,327 
4,402 
4,477 

3,359 
3,454 
3,548 
3,643 

3,738 
3,833 
3,928 
4,024 

4,119 
4,215 
4,311 
4,407 

4,503 
4,600 
4,696 
4,793 

4,890 
4,987 
5,084 
5,182 

5,280 
5,378 
5,476 
5,574 

5,673 
5,771 
5,870 
5,970 

4,200 
4,319 
4,437 
4,556 

4,674 
4,793 
4,912 
5,031 

5,151 
5,270 
5,390 
5,510 

5,631 
5,751 
5,872 
5,993 

6,114 
6,235 
6,857 
6,479 

6,601 
6,724 
6,847 
6,970 

7,093 
7,216 
7,339 
7,463 

5,043 
5,185 
5,327 
5,469 

5,611 
5,754 
5,897 
6,040 

6,183 
6,327 
6,470 
6,615 

6,759 
6,904 
7,048 
7,194 

7,339 

7,485 
7,631 

7,777 

7,924 
8,071 
8,218 
8,366 

5,887 
6,053 
6,218 
6,384 

6,550 
6,717 
6,883 
7,050 

7,217 
7,385 
7,553 
7,721 

7,839 
8,058 
8,227 
8,396 

8,566 
8,736 
8,906 
9,077 

6,731 
6.920 
7,109 
7,299 

7,489 
7,679 
7,870 
8,061 

8,252 
8,443 
8,635 
8,827 

9,019 
9,212 
9,405 
9,599 

7,577 
7.790 
8,003 
8,217 

8,430 
8,644 
8,858 
9,073 

9,288 
9,504 
9,719 
9,935 

8,425 
8,661 
8,898 
9,135 

9,372 
9,610 
9,848 
10,087 



This  table  is  corrected  for  earth  curvature,  refraction,  and  the  height  of  the  instru- 
ment used  at  the  station  (4J  feet). 

23682°— 12 4 


50      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

ELEVATIONS  FROM  VERTICAL  ANGLES. 

When  the  distance  to  a  mountain. or  other  object  is 
known  its  elevation  above  the  surveyor  may  be  deter- 
mined. A  vertical  angle  is  measured  with  a  clinometer 
or  clinometer-compass,  and  the  difference  in  elevation 
can  be  determined  from  the  table.  Information  of  this 
character  assists  greatly  in  the  preparation  of  a  map, 
and  this  method  should  be  used  when  a  peak  is  inacces- 
sible or  not  likely  to  be  occupied  during  the  present  sur- 
vey. If  both  the  distance  and  elevation  of  a  peak  are 
known,  and  the  surveyor  desires  the  elevation  of  the 
station  which  he  is  then  occupying,  this  process  is 
easily  reversed.  The  table  is  prepared  to  miles  of  dis- 
tance, and  if  intermediate  fractional  miles  are  needed 
the  ratio  may  be  interpolated. 

The  method  of  determining  the  distance  of  a  peak  or 
other  salient  topographic  point  is  illustrated  in  the 
various  plane-table  methods.  If  compass  sights  are 
taken  from  two  or  more  known  points  the  intersections 
may  be  platted  with  a  protractor  or  computed.1 

i  The  following  is  the  method  of  computing  the  sides  of  a  triangle  when  two  angles 
and  one  side  are  known:  The  angle  opposite  the  known  side  is  equal  to  180°  minus 
the  sum  of  the  two  known  angles.  The  sine  of  an  angle  is  the  same  as  its  departure 
(in  the  traverse  table)  for  distance  1.  A  and  B  represent  the  two  known  angles 
and  their  distance  apart;  C  is  the  opposite  angle: 

Distance  ^^Xsine  of  angle  B 

Sine  of  angle  C 
Or: 

Distance  ^.BXsine  of  angle  A 

Sine  of  angle  C        —distance  1K7 

The  traverse  table,  distance  1,  being  the  same  as  a  table  of  natural  cosines  and  sines, 
may  be  used  to  change  a  slope  measurement  to  a  horizontal  measurement,  and  also 
get  the  difference  in  elevation.  Thus  a  distance  of  10.00  chains  up  or  down  a  7°  slope 
would  represent  9.92  chains  on  the  level,  and  1.22  chains  rise  or  fall.  The  same  method 
is  used  in  reducing  stadia  measurements. 


TYING  IN.  51 

TYING   IN. 

It  is  frequently  necessary  to  make  surveys  of  ranger 
stations  or  for  timber  sales  in  areas  which  have  not  been 
previously  surveyed  or  mapped.  It  is  imperative  that 
some  connection  should  be  surveyed  between  the  near- 
est or  most  convenient  established  point  and  the  initial 
point  of  the  survey  which  is  to  be  made.  Otherwise  the 
survey  will  not  determine  the  location  of  the  area  under 
consideration.  The  nature  of  the  country  and  the  dis- 
tance necessary  to  be  run  will  suggest  which  of  the  fol- 
lowing methods  may  be  employed: 

(1)  Measure  a  line  north,  south,  east,  or  west  to  in- 
tersect a  Government  survey  line.     Then  tie  to  the 
nearest  corner,  quarter  corner,  meander  corner,  mile- 
post,  grant  corner,  or  other  point  which  is  of  official 
record. 

(2)  Or  run  a  traverse  (meander)  over  a  road,  trail, 
open  or  easy  country  to  such  points. 

(3)  Or  if  no  land  office  surveys  have  been  made 
nearer  than,  say,  5  miles,  but  there  is  a  Geological  Sur- 
vey sheet,  then  tie  to  a  bench  mark,  triangulation  sta- 
tion, forks  of  a  road,  forks  of  a  stream  which  has  not 
changed  its  bed,  or  a  house  which  is  shown  on  the  sheet. 
Accompany  your  report  with  a  tracing  or  description 
which  will  show  unmistakably  the  point  used.     If  you 
tie  to  a  mineral  monument  or  to  some  corner  of  a  pat- 
ented mining  claim,  give  a  clear  description. 

(4.)  Or  if  no  official  surveys  have  been  made  within 
practicable  distance,  proceed  as  follows:  Establish 
and  witness  a  permanent  monument,  marked  F  S  M- 
This  may  be  at  the  initial  point  of  your  survey.  From 


52       INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

this  point  run  a  traverse  to  some  outlook  where  com- 
pass or  plane-table  bearings  may  be  taken  on  a  number 
of  peaks  or  other  definite  landmarks  which  may  be 
visible.  Give  their  estimated  distances.  State  ap- 
proximately what  unsurveyed  section  the  land  would 
be  in,  or  its  latitude  and  longitude.  The  map  accom- 
panying such  a  survey  should  show  any  divide,  stream, 
or  trail  in  the  immediate  vicinity,  and  particularly  the 
name  of  the  watershed. 

BANGER    STATION    SURVEYS. 

When  the  lands  have  been  surveyed  by  the  General 
Land  Office  and  the  corners  can  be  located,  the  plat 
only  need  be  submitted,  showing  the  subdivisions  de- 
sired for  a  ranger  station.  Where  lots  occur  their  num- 
bers should  be  shown  on  the  plat.  No  other  descrip- 
tion is  necessary.  The  determination  of  the  correct 
subdivisions  must  not  be  left  to  conjecture.  The  land 
office  corners  should  be  located  and  the  necessary  lines 
carefully  run  in  every  case  when  there  is  the  least  doubt 
as  to  what  forties  or  tens  should  be  recommended  for 
withdrawal. 

When  the  lands  are  unsurveyed,  or  the  corners  of  the 
Government  survey  can  not  be  located,  the  actual 
boundary  lines  must  be  surveyed  and  marked,  and  field 
notes,  description,  and  a  plat  must  be  prepared,  all  in 
accordance  with  the  following  instructions: 

Three  kinds  of  permanent  points  of  identification  will 
be  established — Forest  Service  Monuments,  to  which  the 
ranger  station  surveys,  and  possibly  future  homestead 
or  timber  surveys,  will  be  tied  by  bearing  and  distance; 


RANGER   STATION    SURVEYS.  53 

corners,  which  will  be  set  up  at  each  angle  in  the  bound- 
ary; and  witnesses,  to  which,  whenever  possible,  each 
monument  and  corner  will  be  tied. 

Forest  Service  Monuments. — The  object  of  these  mon- 
uments is  explained  under  the  subject  "Tying  in." 
They  will  be  similar  to  the  mineral  monuments  of  a 
mining  district.  They  should,  if  possible,  be  immov- 
able and  durable,  and  easy  to  locate  at  any  future 
time  from  the  field  notes'  of  the  survey.  A  large 
bowlder  or  a  built-up  stone  monument  will  serve  the 
purpose,  or  a  sound  tree  of  long-lived  species.  Where 
there  are  no  trees  a  wooden  post  may  be  used.  Monu- 
ments will  be  marked  F  S  M  The  witnesses  for  a 
monument  should  be  permanent  objects  from  which 
at  least  two  cross  bearings  can  be  taken  to  locate  the 
monument  in  the  future  if  necessary.  They  will  be 

marked  ^ 

At  each  angle  in  the  boundary  of  a  ranger  station 
a  durable  corner  will  be  established  similar  to  those  of 
the  land-office  surveys.  Each  corner  post  or  stone 
will  be  marked  near  its  top  with  the  letter  R  and 
below  this  the  number  of  the  angle  at  which  the  cor- 
ner is  set,  beginning  with  the  initial  post  as  number  "j 
and  counting  on  in  regular  sequence  around  the  bound- 
ary in  the  direction  of  the  survey.  Thus  the  monu- 
ment of  the  third  corner  will  be  marked  5 

o 

At  least  two  witnesses  will  be  made  near  each  corner, 
and  will  be  marked  with  the  letter  W  and  the  number 

of  the  corner,  thus:  W 


54      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

If  the  monument  is  established  at  the  initial  point  of 
a  survey,  and  is  therefore  also  corner  number  "\  ,  it 
will  bear  both  monument  and  corner  markings,  thus: 

F  S  M  ?     The  witnesses  will  then  bear  the  letters  M 

M 
with  the  figure  1  beneath,  thus:  w 

The  surveyor  will  depend  largely  on  his  common 
sense  and  skill  in  selecting  trees  or  prominent  rocks 
in  the  best  positions  for  witnesses.  Frequently  the 
corners  can  be  established  near  good  witnesses  without 
diminishing  the  value  of  the  station.  Usually  the  wit- 
nesses should  nob  be  more  than  3  chains  from  a  cor- 
ner— the  nearer  the  better,  but  they  should  be  inside 
the  boundary  if  possible. 

Where  the  boundary  line  of  the  ranger  station  passes 
through  timber,  the  line  should  be  plainly  blazed  in 
the  manner  described  on  page  41. 

The  instructions  regarding  field  notes  (p.  44)  must 
be  followed.  A  good  form  for  keeping  them  is  here 
shown : 

SPECIMEN   NOTES. 

National  Forest. 

WILDCAT  RANGER  STATION. 

T.  25  N.,  R.  8  E.,  Section ,  >  Meridian.  Num- 
ber   List Area,  33.63  acres. 

June  15,  1912. 
Weather  cloudy. 

Variation. — This  survey  was  made  with  a  Forest  Service  standard 
compass.  Variation,  11°  3(K  E.,  was  obtained  by  retracement  of 
east  line  of  Section  36,  T.  25  N.,  R.  7  E.  The  local  land  office  rec- 
ommends using  a  variation  of  31°  to  11°  40'  in  this  vicinity. 


RANGER   STATION    SURVEYS. 


55 


Forest  Service  Monument. — Consists  of  a  bowlder  7/X6/X3/  above 
ground,  situated  on  the  left  bank  of  Wildcat  Creek,  7  chains  down- 
stream from  the  juncture  of  the  north  and  east  forks,  70  links  from 
the  water's  edge,  at  right  angles  to  the  stream.  F  S  M  cut  on  the 


No.  3 
,"2: 


^ 


and 


j 

*  o 


:NO.I 


WILDCAT  RANGER  STATION 

In  unsurveyed  section TZ5  N.  R.8E. 

NATIONAL  FOREST 

Scale lnches  =  l  Mile. 

Surveyed  by  John  R. Underwood 

Variation   ll°30'  E. 

June   I5™-I9I2 


FIG.  11.— Ranger  station  plat. 

highest  point  of  the  rock,  whence  a  yellow  pine  16  inches  in  diam- 
eter bears  N.  16°  E.,  73  links  distant,  marked  JJJ  in  blaze.  Lyon 
Mountain  bears  S.  31°  30'  W.  Tiger  Mountain  bears  N.  28°  30'  W. 
Rock  ledge  bears  S.  54°  W.,  47  links  distant,  marked  JJ 


56      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

Beginning  at  corner  No.  1,  a  limestone  30"  X  9"  X 5"  set  in  mound 

p 

of  stones  and  chiseled  !j 

Forest  Service  Monument  above  described  bears  S.  13°  W.,  252 
links  distant. 

The  SW.  corner  of  the  ranger's  cabin,  built  in  1905,  bears  N.  18° 
E.,  180  links  distant. 

A  yellow  pine,  12  inches  diameter,  bears  east,  298  links  distant 

marked  YX 

Thence  N.  58°  E. 

1.20  chs.  road,  N.  and  S. 
12.40          ravine,  course  NW. 

17.80          leaning  scrubby  pinon  16  inches  diameter. 
25.00          enter  scattering  juniper  and  pinon. 
26.50          East  Fork  Wildcat  Creek  flows  N.  89°  W. 

35.00          corner  "No.  2,  a  juniper  post  5/X4//X4/<'  in  mound  of  gravel 

p 
and  earth,  at  foot  of  slope,  marked  ^ 

A  pinon,  8  inches  diameter,  bears  north  10  links   distant, 

marked   X 
A  granite  bowlder,  4  feet  in  diameter  and  3  feet  above 

ground,  bears  S.  82°  E.,  223  links  distant,  marked  ^ 

Thence  N.  15°  W. 

2.00          ascend  slope,  through  small  scrubby  pinon. 

10.00          corner  No.  3,  a  limestone  3"X7//X26//  in  mound  of  stone, 

p 
marked  3  on  SW.  slope  of  a  hill,  about  150  feet  above  the 

ranger  cabin. 

Chimney  of  cabin  bears  S.  45°  307  W. 
No  suitable  witness  objects  within  3.00  chains. 


RANGER   STATION   SURVEYS.  57 

Thence  S.  58°  W. 

(There  is  evidently  local  attraction  at  this  point,  since 
my  backsight  reading  is  S.  14°  E.     The  compass  needle 
therefore  reads  S.  59°  W.  on  this  course.) 
Running  down  slope. 
12.60          ravine,  course  south. 

26.80          foot  of    slope.     Leave  pinon,  enter  willows  and  cotton- 
wood. 

28.53          cross  north  fork  of  Wildcat  Creek,  flows  S.  18°  E. 
29.00          enter  open  yellow  pine  timber. 
35.00          corner  No.  4.     A  stake  of  pine  heartwood  in  mound  of 

p 
earth,  marked  2 

A  yellow  pine,  2  feet  in  diameter,  bears  N.  14°  E.,  18 

W 

links  distant,  marked  V 

A  fir,  12  inches  diameter,  standing  on  right  bank  of  north 
fork  of  Wildcat  Creek,  bears  S.  42°  30'  E.,  134  links  dis- 
tant, marked  ^ 

(As  my  backsight  reading  is  now  N.  58°  E.,  I  conclude 
that  there  is  no  local  attraction  at  this  point.) 

Thence  S.  15°  E. 

through  open  pine  timber. 
2.96          pine  tree  2£  feet  in  diameter. 
5.00          leave  pine  timber. 
7.24          cross  Wildcat  Creek  flows  S.  23°  W. 

10.09          corner  No.  1,  the  place  of  beginning,   containing  33.63 
acres  of  land,  be  the  same  more  or  less. 

JOHN  R.  UNDERWOOD. 

Ranger  Surveyor. 
Field  notes  and  plat  compared  and  approved  by — 

GEORGE  A.  OVERMAN, 

Supervisor. 


58      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 
FOREST   HOMESTEAD    SURVEYS. 

These  surveys  will  be  made  in  the  same  manner  as 
those  for  ranger  stations,  but  to  avoid  some  confusion 
and  to  distinguish  them  the  following  system  of  marks 
should  be  used : 

Forest  Service  monuments,  which  are  established  for 
homestead  surveys,  will  be  marked  F  S  M  H  ^Wit- 
nesses for  these  monuments  will  be  marked  ,A,  Cor- 

W 

ners  will  be  marked  with  H  and  the  number  of  the 
corner,  thus:  ~  and  a  witness  to  the  same  corner  will 

be  ^p^  When  a  monument  is  also  the  initial  point  of 
the  survey,  and  is  therefore  also  corner  number  1  it 
will  bear  both  marks,  thus:  F  S  M  H 

If  a  F  S  M  is  subsequently  used  as  a  tie  for  a  forest 
homestead  survey  its  original  marks  will  not  be  changed. 
In  like  manner  a  F  S  M  H  may  be  used  as  a  tie  for  a 
ranger  station  or  other  subsequent  survey  without 
changing  the  original  marks.  The  field  notes  will,  of 
course,  show  unmistakably  what  tie  was  used. 

The  type  of  cover  of  the  land  must-  be  clearly  shown 
on  the  map  accompanying  the  reports.  For  this  pur- 
pose Forest  Atlas  Legend  crayons  or  color  tints  will  be 
used. 

The  establishment  of  corners  will  not  be  required 
where  it  can  be  conclusively  shown  in  a  written  report 
that  listing  of  the  land  should  be  denied. 

The  surveyor  should  be  thoroughly  familiar  with  the 
instructions  under  the  act  of  June  11,  1906.  Attention 


TRAIL  SURVEYS.  59 

is  also  called  to  the  circular  of  the  General  Land  Office, 
September  7,  1906,  "  Regulations  Governing  Entries 
within  Forest  Reserves." 

A  cooperative  agreement  between  the  Departments 
of  the  Interior  and  Agriculture ,  da  ted  Sep  tember  1 9 , 1 9 1 1 , 
to  avoid  duplication  or  unnecessary  work  in  surveying 
forest  homestead  claims,  provides  that  instead  of  two 
surveys,  as  heretofore  required,  there  shall  be  but  one 
survey,  and  that  it  may  be  made  by  a  forest  officer, 
designated  by  and  acting  under  the  direction  of  the 
surveyor  general,  "who  will  exercise  supervision  in 
every  case  as  to  the  manner  of  the  execution  of  the 
survey  with  reference  to  the  running  of  lines  and  the 
establishment  of  monuments  to  mark  the  same." 

Such  surveys  are  for  the  approval  of  the  surveyor 
general  and  acceptance  by  the  General  Land  Office. 
The  instructions  of  the  surveyor  general  will  be  fol- 
lowed in  these  cases,  even  though  they  conflict  entirely 
or  in  part  with  the  methods  of  the  Forest  Service. 

TRAIL,    SURVEYS. 

In  surveying  for  railways,  roads,  or  trails,  the  vertical 
deflection  of  the  line  is  always  expressed  in  per  cent. 
Thus,  a  5  per  cent  grade  means  a  rise  of  5  feet  in  100 
feet  of  horizontal  distance.  The  horizontal  deflection 
of  the  line  is  always  expressed  in  degrees.  Thus,  a  rail- 
way may  have  a  3°  curve,  which  is  a  horizontal  deflec- 
tion of  3°  in  100  feet,  from  chord  to  chord,  or  a  road 
may  have  a  change  in  direction  of  3°  at  the  junction 
of  two  courses.  Percentage  of  grade  and  degrees  of 
azimuth  should  never  be  confounded,  as  very  serious 
errors  will  result.  The  terms  are  never  interchangeable. 


60      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

The  most  important  thing  about  a  trail  is  its  grade. 
Any  other  feature  of  its  construction  may  be  improved 
from  month  to  month  or  from  year  to  year,  but  if  the 
grade  is  not  properly  established  it  must  in  time  be 
abandoned.  Thus,  not  only  may  time  and  money  be 
wasted,  but  the  trail,  while  in  use,  would  be  unsatis- 
factory. On  the  other  hand,  if  the  grade  is  properly 
located,  the  trail  will  be  useful  as  soon  as  it  is  passable. 

The  best  gradient  between  any  two  points  is  upon 
a  line  which  would  have  the  same  percentage  of  rise 
from  beginning  to  end.  Often  there  are  "  salient 
points"  along  the  route,  above  or  below  which  the 
grade  must  run,  and  we  must  then  think  of  the  line  as 
divided  into  parts,  each  with  its  own  percentage  of  rise 
between  these  salient  points.  If  an  even  gradient  is 
also  a  low  gradient,  it  is  unquestionably  the  proper 
location  for  the  trail  if  construction  is  practicable.  The 
same  is  true  if  the  gradient  is  on  the  most  direct  and 
practical  route  and  is  below  the  maximum  for  trails. 

Reverse  grades  should  be  avoided  if  possible.  This 
means  that  we  should  never  go  downhill  when  the 
object  is  to  go  uphill,  as  this  obviously  increases  the 
elevation  to  be  climbed,  and  therefore  increases  the 
grade  upon  the  ascending  portions  of  the  trail. 

There  are  three  maxima  grades  for  trail  construction. 
These  are:  6  per  cent,  12  per  cent,  and  18  cer  cent. 
Being  multiples  of  6,  these  are  easy  to  remember,  as 
are  also  the  reasons  for  having  several  maxima.  A 
good  grade,  having  a  maximum  of  6  per  cent,  may  later 
be  developed  into  a  first-class  road  or  turnpike.  Such 
a  grade  might  be  called,  for  convenience,  a  turnpike 


TRAIL,  SURVEYS.  61 

grade.  The  surveyor  should  try  his  very  best  to  get 
the  trail  upon  a  turnpike  grade,  but  if  this  is  obviously 
impracticable,  he  should  keep  the  grade  as  low  as  pos- 
sible, and  not  exceed  12  per  cent.  This  is  the  limit 
for  safe  mountain  roads  such  as  are  used  for  freighting, 
and  might  properly  be  called  a  freight  grade.  When 
trails  must  be  constructed  upon  grades  steeper  than 
this,  or  to  places  which  roads  can  not  reach  for  many 
years,  it  is  simply  a  case  of  making  the  best  location 
the  circumstances  permit.  However,  there  is  still  the 
final  limit  which  should  not  be  exceeded.  This  is  the 
trail  grade  of  18  per  cent,  and  is  as  steep  as  a  loaded 
pack  animal  can  ascend  without  violent  and  exhaustive 
effort.  Long  steep  grades  should  have  breaks  at  inter- 
vals where  animals  may  rest  and  recover. 

In  deciding  on  a  route  or  location,  the  following 
points  should  be  considered. 

(1)  A  south  exposure  has  less  snow,  is  dryer,  often 
more  open,  and  has  an  increased  fire  hazard. 

(2)  Slide  rock  and  other  unstable  material  make  a 
temporary  or  dangerous  tread. 

(3)  Steep  side  hills,  near  the  angle  of  repose,   are 
liable  to  landslides  or  snowslides. 

(4)  Bridges    and    temporary    structures    should    be 
avoided  as  far  as  possible. 

(5)  The  permanence  of  a  trail  depends  on  the  material 
and  its  drainage. 

It  will  be  seen  from  the  above  that  the  location  of  a 
trail  grade  is  almost  wholly  a  matter  of  experience  and 
good  judgment 


62       INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

The  aneroid  barometer  is  often  used  to  determine 
the  distance  in  elevation  between  the  ends  of  the  pro- 
posed trail,  and  the  approximate  distance  may  be  de-' 
termined  by  pacing.  This  furnishes  a  preliminary 
reconnaissance.  A  "  trial"  or  "random"  line  may  then 
be  run  from  one  end  of  the  proposed  line  to  the  other 
on  the  approximate  average  grade,  which  has  been  de- 
termined by  reconnaissance.  This  may  be  done  by  a 
grademeter,  an  Abney  level,  or  a  Locke  level. 

The  grademeter  is  used  as  described  on  page  29. 
As  the  circular  pendulum  is  graduated  to  tangents  it 
may  be  used  to  line  in  the  grade  to  any  desired  per  cent, 
either  uphill  or  downhill.  It  is  unnecessary  to  consider 
the  matter  of  distance,  because  grade,  as  thus  meas- 
ured, is  an  absolute  quantity  in  itself. 

The  Abney  level  is  used  in  a  similar  manner,  but  it 
contains  no  swinging  pendulum,  and  must  be  set  to  the 
desired  grade  before  the  sight  is  taken  to  the  instru- 
ment. Some  of  the. Abney  levels  are  graduated  to 
degrees ;  others  to  degrees  and  slopes,  in  the  proportion 
of  1 : 1  and  1 : 10;  others  have  graduations  for  per  cent. 
This  has  led  to  some  confusion,  and  some  bad  construc- 
tion has  resulted.  Care  should  be  used  to  apply  only 
the  per  cent  when  this  instrument  is  in  use  on  trails. 

The  Locke  level  is  a  simple  hand  level  which  does  not 
sight  either  uphill  or  downhill ;  it  is  used  by  sending  an 
assistant  ahead  with  a  pole,  upon  which  sights  are  taken 
through  the  barrel  of  the  level.  Allowance  must  be 
made  for  the  height  of  the  surveyor's  eye  above  the 
ground.  Thus,  if  his  eye  is  5  feet  above  the  ground 
he  can  fix  the  location  of  a  5  per  cent  grade  by  working 


TRAIL  SURVEYS.  63 

uphill  and  taking  a  sight  on  the  ground  at  a  point  100 
feet  distant,  or  by  sighting  downhill  at  the  top  of  a  pole 
which  is  10  feet  high  and  100  feet  distant. 

For  running  different  gradients,  of  course  the  height  of 
the  surveyor's  eye  remains  the  same,  and  the  length  of 
the  sight  is  changed  according  to  the  grade.  Thus,  a 
sight  on  a  10-foot  pole,  looking  downhill,  in  a  distance 
of  50  feet,  would  give  a  10  per  cent  grade;  and  a  sight, 
uphill,  on  the  ground  at  a  distance  of  50  feet,  would  give 
a  10  per  cent  grade,  still  assuming  the  height  of  the  sur- 
veyor's eye  to  be  5  feet.  In  the  same  manner,  if  the 
sights,  both  uphill  and  downhill,  were  200  feet,  the 
grade  would  then  be  2J  per  cent. 

The  use  of  these  instruments  is  to  some  extent  a  mat- 
ter of  individual  preference. 

In  the  large  majority  of  cases  the  grade  should  be 
located  by  a  downhill  survey.  This  is  always  the  case 
when  a  pass  or  saddle  is  the  salient  high  point.  When 
the  grade  connects  two  salient  points  the  location  may 
be  run  in  either  direction.  The  alignment  of  the  trail, 
or  its  meanders,  may  be  determined  by  a  compass  sur- 
vey after  the  trail  is  constructed.  It  is  a  matter  of  sec- 
ondary importance  and  should  be  given  no  considera- 
tion if  it  takes  any  time  which  might  have  been  spent 
in  getting  the  best  possible  grade.  The  importance  of 
alignment  should  not  be  entirely  overlooked,  however, 
and  where  two  or  more  routes  would  give  equally  satis- 
factory grades,  then  the  one  should  be  chosen  which  will 
have  the  most  favorable  alignment,  together  with  short- 
ness of  distance,  and  which  will  require  the  least  number 
of  bridges  and  culverts,  and  in  other  respects  afford  the 
most  favorable  conditions  for  construction. 


64      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 
PLATTING  THE    SURVEY. 

When  a  plane  table  is  used,  the  survey  and  platting 
progress  together,  but  if  other  methods  are  used  it  is 
necessary  to  "plat"  the  notes.  This  should  be  done  on 
the  prescribed  forms,  using  one  of  the  standard  scales 
which  are  described  on  page  66.  Be  sure  that  the  plat 
shows  the  scale,  as  well  as  "what  it  is,  where  it  is,  who 
made  it,  and  the'date."  If  the  plat  does  not  "close/' 
throw  the  error  into  the  sides  or  angles  which  are  most 
liable  to  be  inaccurate  on  account  of  difficulties  in  the 
field  work.  If  local  attraction  was  encountered  at  one 
corner  the  error  is  likely  to  be  in  that  angle.  If  offsets 
were  made,  or  very  rough  or  steep  country  traversed  on 
one  side,  the  mistake  is  probably  in  the  chaining  of  that 
side.  An  error  of  one  link  to  the  chain  is  allowable.  If 
a  larger  error  appears  in  platting,  the  field  work  must 
be  repeated. 

MAP  MAKING  IN    THE  FIELD. 

After  the  salient  points  of  the  topography  have  been 
located  by  plane  table,  and  the  roads,  streams,  or  sum- 
mits have  been  traversed  by  compass  surveys,  it  remains 
for  the  surveyor  to  sketch  in  the  contours.  Some  of 
this  may  l><3  done  when  the  peaks  are  located  and  when 
the  distances  are  chained,  and  the  result  is -a  skeleton 
map  upon  which  it  remains  to  fill  in  the  balance  by  the 
eye.  This  is  a  matter  of  practice.  It  is  an  excellent 
plan  to  learn  to  read  contour 'maps,  such  as  are  pub- 
lished by  the  Geological  Survey,  and  the  student  should 
provide  himself  with  a  topographic  sheet  of  some 
region  with  which  he  is  well  acquainted  and  learn  to 


MAP  MAKING  IN   THE  FIELD.  65 

identify  the  relief  with  its  contours.  When  this  is  mas- 
tered a  good  contour  map  will  be  almost  as  graphic  as  a 
miniature  model  of  the  country. 

In  sketching  contours  it  is  of  great  assistance  to 
imagine  the  sea  level  raised.  Thus,  if  the  5,000-foot 
contour  is  being  sketched,  we  may  imagine  that  the 
salt  waters  of  the  earth  are  raised  5,000  feet  higher  than 
they  now  are.  It  is  evident  that  the  true  contour 
would  follow  the  shore  line  which  is  thus  imagined  and 
that  bays  and  harbors,  islands,  straits,  etc.,  would 
result.  It  is  evident  that  contour  lines  can  not  cross 
each  other  or  themselves  and  that  they  must  connect 
somewhere,  either  on  the  map  which  is  being  prepared 
or  in  some  other  region. 

The  contour  map,  when  thus  prepared,  is  only  a  base 
map  for  other  data  to  be  collected  for  the  Forest  Service. 
Some  of  this  data  may  be  collected  as  the  survey  pro- 
ceeds, such  as  the  classification  of  the  land,  timber, 
woodland,  barren,  etc.,  or  the  composition  and  stand  of 
a  forest.  When  the  plane-table  map  is  being  made  in 
the  field,  the  paper  is  necessarily  covered  with  pencil 
notes  and  lines  which  give  the  names  of  points,  eleva- 
tions, directions,  etc.  There  is  no  need  to  encumber  this 
map  with  other  figures  or  names  which  may  be  confus- 
ing or  lead  to  error.  A  better  plan  is  to  cover  the  map 
with  a  piece  of  tracing  cloth,  with  the  dull  side  up, 
which  may  be  thumb-tacked  along  one  side  only,  that 
it  may  hang  back  out  of  the  way  when  work  is  being 
done  on  the  base  map.  On  this  the  burns,  windfalls, 
barren  areas,  or  stand  may  be  sketched  either  in  black 
or  with  colored  crayons  without  smearing  the  base 

°-12 5 


66      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

map  or  obliterating  any  of  its  topographic  data.  Some 
salient  points  on  the  base  map  should  be  copied  on  the 
tracing  cloth  so  that  the  two  may  be  registered  at  any 
time,  for  the  paper  may  shrink  or  the  cloth  may  stretch- 

THE  FOREST  ATLAS. 

The  Forest  Atlas  at  Washington  is  the  central  depository 
for  maps,  diagrams,  statistics,  and  history  of  the  National 
Forests  and  forestry  in  general  throughout  the  world. 
Its  most  important  division  is  that  of  maps,  and  the 
most  important  maps  are  those  of  the  National  Forests. 

The  Forest  Atlas  now  cotnprises  190  volumes,  con- 
taining sheets  exactly  18  by  21  inches.  They  are  bound 
in  loose-leaf  holders  in  two  ways.  Standard  binders 
have  the  binding  margin  on  the  21-inch  side,  while  town- 
ship  binders  have  the  binding  margin  on  the  18-inch  side. 
No  map  is  made  on  a  sheet  less  than  18  by  21  inches, 
and  larger  maps  are  made  on  two  or  more  sheets  which 
are  always  numbered  from  west  to  east  beginning  at 
the  northwest  corner.  Borders  are  omitted.  The 
title  consists  only  of  the  name  of  the  forest  or  the 
number  of  the  township.  The  top  of  the  map  is 
always  north.  A  binding  edge  of  at  least  1J  inches  is 
always  left  blank  on  the  west  or  left-hand  side  of  each 
sheet. 

The  standard  scale  of  the  Forest  Atlas  is  1  inch  to  1 
mile,  and  the  National  Forests  have  been  practically 
covered  by  atlas  sheets  according  to  this  standard. 
Whenever,  in  special  cases,  a  larger  or  smaller  scale  is 
necessary  for  the  preparation  of  any  map  in  the  Forest 
Service,  it  must  sustain  the  simple  relation  of  X  2 


THE  FOREST  ATLAS.  67 

or  -*-  2.  Thus  the  scale  may  be  2  inches,  4  inches,  or  8 
inches  to  1  mile;  or  i  inch,  J  inch,  or  J  inch  to  1  mile. 
Under  no  circumstances  will  sheets  be  prepared  for  the 
Forest  Atlas  on  the  ratio  of  3,  5,  7,  etc.  The  scale  of 
township  plats  is  2  inches  to  1  mile,  because  that  scale 
was  adopted  by  the  General  Land  Office,  from  which 
the  plats  were  procured. 

The  Atlas  sheets  which  cover  a  National  Forest  are 
called  Si  folio  and  are  assembled,  with  a  legend  page,  in  a 
paper  cover,  on  which  is  printed  an  index  diagram  show- 
ing the  number  of  the  sheets. 

In  the  office  of  each  district  forester  is  a  District 
Atlas  consisting  of  20  or  more  volumes,  containing 
duplicate  sheets  of  the  Forest  Atlas  covering  the  area 
of  the  district.  Whenever  Forest  Atlas  folios  have 
been  duplicated  by  photolithography  or  otherwise  for  a 
National  Forest,  the  officers  have  been  supplied  with  cop- 
ies, but  under  no  circumstances  are  copies  of  any  atlas 
folio  to  be  sold  or  given  away.  They  are  strictly  for  the 
use  of  forest  officers  in  the  administration  of  the  National 
Forests.  Copies  for  distribution  are  not  published. 

Forest  Supervisors  are  supplied  by  the  property  clerk 
with  binders  for  Forest  Atlas  folios,  having  the  binding 
margin  on  the  21 -inch  side,  and  also  with  binders  for 
Land  Office  township  plats,  having  the  binding  margin 
on  the  18-inch  side. 

The  folios  are  the  "mother  maps"  which  furnish  the 
bases  from  which  further  map  making  will  proceed  in 
the  Forest  Service.  They  correspond  to  the  mother 
maps  of  other  countries  in  this  respect — that  they  are 
compiled  from  official  data  upon  a  standard  scale,  1 


68      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

inch  to  1  mile,1  and  upon  a  uniform  legend.  They  are 
not  always  sufficiently  accurate  for  forest  work,  and 
the  sheets  must,  therefore,  be  corrected  whenever  new 
data  have  been  obtainsd  in  the  field.  The  manner  of 
correcting  sheets  is  shown  on  the  '  'dummy  Atlas  sheet," 
which  has  been  issued  to  forest  officers.  The  method 
is  that  used  by  printers  in  correcting  proof.  Bold  lines 
should  be  drawn  to  the  margin  of  the  sheet  and  explan- 
atory notes  written  clearly.  Do  not  make  neat  cor- 
rections without  the  marginal  note,  or  it  will  not  be 
apparent  that  the  sheet  has  been  corrected.  Do  not 
write  letters  or  memoranda  telling  how  a  sheet  should 
be  corrected.  Do  it  yourself.  Do  not  be  afraid  to  mark 
up  any  sheet  because  it  is  beautifully  engraved  or  col- 
ored. Your  corrections  will  make  it  more  valuable. 

New  data  obtained  by  reconnaissance  is  usually 
mapped  on  a  scale  of  2  inches  or  4  inches  to  1  mile. 
Such  data  should  not  be  redrawn  to  the  standard  Atlas 
scale  in  the  field.  The  reconnaissance  tracings  should 
be  sent  to  Washington  with  a  requisition,  Form  988, 
for  photoreduction.  For  this  and  other  reasons  recon- 
naissance tracings  and  other  base  maps  should  be 
drawn  with  black  ink  only,  and  should  show  only  the 
drainage,  contour,  culture,  and  land  lines.  Other  data, 
such  as  classification,  forest  or  grazing  types,  or  admin- 
istration districts,  can  be  shown  by  appropriate  colors 
upon  two  or  more  prints.  By  this  method  the  tracing 
remains  a  record  which  is  subject  to  very  little  change, 

1  The  mother  maps  of  Great  Britain  and  India  are  on  the  same  scale  as  the  Forest 
Atlas  standard.  Those  of  France,  Spain,  Italy,  Switzerland,  and  Sweden  are  nearly 
the  same,  1J  inches  to  the  mile.  Those  of  Bosnia,  Herzegovina,  Norway,  Bulgaria, 
Hungary,  Russia,  and  Portugal  are  on  smaller  scales;  those  of  Germany,  Belgium, 
Denmark,  and  the  Netherlands  are  on  larger  scales. 


THE  FOREST  ATLAS. 


69 


CONVENTIONAL  SIGNS 

Wagon  road 
=  Secondary  road 
--Trail 
**•  Rail  road 

Telegraph  line 

Telephone  line 

Power  line  i 

Pipeline 

Aqueduct 

Fence 

Ditch 

Flume 

Bridge 

Corral 

Supervisors  headquarters 

Rangers  h'dfcjrs,  no  house 

Rangers  rfdbj'rfe.with  house 

House  ^ 

Railroad  station  B 

Stage  station  A 

Power  station 


T    Hotel 
J    Store 
ii    School 
+    Church 
£3    Cemetery 
•  TEL. Telegraph  office 
*TLP.  Telephone  office 
It    Cabin 
&L    Logging  camp 
-cx-  Savymi  1 1,  portable 
-A-  Sawmill, stationary 
-^-  Grist  mill 

Grist  and  sawmill 

Apiary 

Windmill 

Well 

Quarry  or  gravel  pit 

Mine  location,  unpatented 

Mine  shaft 

Triangulat'ion  station 


A 
AA 


m 
7^ 


Scale 
i 


39° 

(omit  borders 

and  3calefrom 

Border  for 

Atlas  Sheets) 

General  Map; 

Bo 

Fo 

115°                                         R.3W. 

3  Miles 


T.I9N 


Border  for 
Maps 


70      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

LETTERING. 


ABCDEFGHIJKLMNOPQRSTUVWXYZ 
abcdefghijklmnopqrstuvwxyz  123456789 

(topography) 

UPPER  CASE  USED  FOR  TITLES  MOUNTAIN  RANGES,  STATE  NAMES, 
TOWNSHIP  AND  RANGE  NUMBERS,  GRANTS,  AND  RESERVATIONS,  ALPHA- 
NUMERIC SYMBOLS. 

Upper  and  Lower  Case  for  Peaks,  Valleys,  Islands,  Capes,  etc.,  Meridians  and 
Parallels,  Legends  and  Scales. 

ABCDEFGHIJKLMNOPQRSTUVWXYZ 
abcdefghijklmnopqrs  t  u  v  w  x  y  z   123456789 

(culture) 

UPPER   CASE  FOR  RAILROADS,   ROADS,    TELEPHONE  LIMES,  AND 
OTHER  MEANS  OF  COMMUNICATION. 

Upper  and  Lower  Case  for  Other  Culture. 

ABCDE  FGH  UK  LM^OPQItSTU  V  WX  YZ 

abcdef ghi  j  klmnopqr  st  u  v  wxy  z     123456789 

( settlement) 

UPPER  CASE  FOR  CITIES,  STATE,  AND  COUNTY  BOUND- 
ARIES. 

Upper  and  Lower  Case  for  Towns,  Villages,  Post  Offices. 

ABCDEFGHIJKLMNOPQItSTUVWXYZ 
abcdef ghijMmnopqrstuvwxyz  123436789 

(water) 
UPPER  CASE  FOR  OCEANS,  LARGE  RIVERS,  LAKES,  ETC. 

Upper  and  Lower  Case  for  Small  Rivers,  Creeks,  Springs,  Marshes, 
Glaciers,  Canals,  Ditches,  etc. 


THE  FOREST  ATLAS.  71 

and  is  not  obscured  by  data  which  is  of  special  rather 
than  general  value.  The  first  reconnaissance  of  any 
area  should  include  the  drainage  and  contour,  otherwise 
it  will  not  be  possible  to  '  'register7'  a  second  or  supple- 
mental reconnaissance  with  it. 

General  maps,  showing  an  entire  Forest  or  region  are 
compiled  at  Washington  from  data  on  the  corrected 
Atlas  sheets,  and  are  issued  for  the  use  of  forest  officers. 
The  usual  process  is  photolithography.  Every  request 
for  the  issuance  of  a  map  should  be  submitted  to  the 
Forester  with  a  recommendation  regarding  the  data  to 
be  shown  or  omitted,  scale,  kind  of  paper,  and  number 
of  copies  required.  Any  project  for  the  issuance  of  a 
"three-color  map"  with  blue  drainage,  brown  con- 
tours, and  black  culture  should  be  taken  up  by  corre- 
spondence with  the  Forester  before  the  final  tracings 
are  prepared,  in  order  that  the  manuscript  may  be  in 
good  shape  for  the  engraver. 

The  Forest  Atlas  legend  page,  which  has  been  sup- 
plied to  all  forest  officers,  shows  the  standard  scheme 
of  colors  and  symbols  which  are  used  in  the  prepara- 
tion of  all  atlas  sheets. 

It  should  be  borne  in  mind  that  National  Forests  are 
established  in  widely  different  regions;  as  far  north  as 
Alaska  and  as  far  south  as  Florida  and  Porto  Rico. 
On  no  two  forests  will  the  data  suggested  on  the  legend 
page  be  of  equal  importance,  and  it  may  be  necessary 
or  convenient  to  adopt  additional  symbols  or  colors  to 
show  unusual  conditions.  This  is  quite  permissible 
providing  the  marginal  notes  are  made  explanatory  or 
if  the  sheet  is  subject  to  only  one  interpretation  by 
forest  officers  who  will  have  to  use  it. 


72      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  E1C. 

An  atlas  sheet  or  any  other  map  should  show  plainly 
the  information  it  is  intended  to  convey,  and  artistic 
flourishes,  fancy  type,  or  border  designs  are  useless. 
It  should  show  what  it  is,  where  it  is,  the  scale,  who 
made  it,  and  the  date.  It  should  show  also  by  whom 
the  field  examination  or  survey  was  made  and  the  date 
of  the  same.  If  it  is  from  an  original  survey  the  mag- 
netic variation  should  be  given.  On  the  borders  of  the 
map,  if  the  area  shown  covers  more  than  one  township, 
the  township  and  range  numbers  should  be  given,  and 
also,  if  possible,  one  or  more  meridians  and  parallels. 
If  a  degree  meridian  does  not  fall  in  the  map,  then 
some  intermediate  may  be  given,  such  as  10'  or  20 '. 
Table  7  will  be  found  convenient. 

TABLE  7. — Lengths  of  degrees  on  meridians  and  parallels  at  different 
latitudes  on  the  earth. 


At  lati- 
tude— 

Length  of  1° 
on  meridians. 

Length  of  1° 
on  parallels. 

Convergence  in 
one  township 
or  in  two 
meridians  6 
miles  long  and 
6  miles  apart. 

Miles. 

Miles. 

Links. 

26° 

68.84 

62.21 

35.4 

27 

68.85 

61.68 

37.0 

28 

68.86 

61.12 

38.6 

29 

68.87 

60.55 

40.2 

30 

68.88 

59.96 

41.9 

31 

68.89 

59.34 

43.6 

32 

68.90 

58.72 

45.4 

33 

68.91 

58.07 

47.2 

34 

68.92 

•57.  41 

49.1 

35 

68.93 

56.72 

50.9 

36 

68.95 

56.03 

52.7 

37 

68.96 

55.31 

54.7 

38 

68.97 

54.58 

56.8 

39 

68.98 

53.83 

58.8 

40 

68.99 

53.06 

60.9 

41 

69.01 

52.28 

63.1 

42 

69.02 

51.48 

65.4 

43 

69.03 

50.67 

67.7 

44 

69.04 

49.84 

70.1 

45 

69.05 

49.00 

72.6 

46 

69.07 

48.14 

75.2 

47 

69.08 

47.26 

77.8 

48 

69.09 

46.37 

80.6 

49 

69.10 

45.47 

83.5 

THE  FOREST  ATLAS.  73 

The  atlas  sheets  show  the  alienation  of  lands  within 
National  Forests,  but  it  must  be  understood  that  data 
of  this  kind  can  not  be  accepted  as  final  authority,  but 
may  be  regarded  as  presumptive  evidence.  It  has  re- 
quired three  years  to  collect  the  alienation  data  for  the 
National  Forests,  and  since  their  status  changes  from 
day  to  day,  while  the  compilation  and  publication  of 
atlas  sheets  requires  several  months,  it  is  evident  that  a 
folio  can  not  be  issued  to  forest  officers  which  will  be 
up  to  date  in  this  respect.  It  is  only  by  keeping  new 
data  posted  on  the  sheets  that  the  office  record  can  be 
kept  up  to  date. 

Maps  are  never  perfect,  nor  do  they  approach  perfec- 
tion unless  repeatedly  altered  and  corrected  in  accord- 
ance with  dicoveries  or  changed  conditions.  Although 
the  Forest  Atlas  sheets  are  compiled  in  every  case 
from  the  best  data  available,  they  are  often  far  below 
the  standard  which  should  obtain  in  forest  maps. 
It  will  not  be  regarded  as  a  reflection  upon  the  compiler 
of  a  sheet  if  a  large  number  of  corrections  are  found 
necessary,  and  field  officers  should  never  hesitate,  for 
this  reason,  about  sending  in  data. 

The  coloring  tints  which  are  used  in  the  classification 
scheme  may  be  prepared  as  follows  from  standard  inks 
that  will  be  furnished  by  the  property  clerk  at  Ogden, 
upon  requisition : 

Forest  Atlas — Color  prescriptions, 
Timberland: 

Less  than  2,000  board  feet  per  acre —  Parts. 

Green  ink 2 

Yellow  ink 1 

Water 3 


74      INSTRUCTIONS  TOR  MAKING  FOREST  SURVEYS,  ETC. 

Timberland — Continued. 

2,000  to  5,000  board  feet  per  acre—  Parts. 

Green  ink 1 

Water 3 

5,000  to  10,000  board  feet  per  acre — green  ink. 

10,000  to  25,000  board  feet  per  acre- 
Brown  ink 3 

Green  ink 3 

Yellow  ink 

25,000  to  50,000  board  feet  per  acre- 
Brown  ink 4 

Green  ink 

Yellow  ink 1 

Water 7 

Woodland,  cord  wood,  etc.: 

Green  ink 1 

Yellow  ink 2 

Water 8 

Chaparral  or  brush: 

Brown  ink 1 

Water . .  5 

Sagebrush: 

Brown  ink 3 

Yellow  ink 

Orange  ink 

Water 10 

Grassland,  parks,  etc.: 

Yellow  ink 

Water 1 

Barren  land: 

Black  ink 1 

Water 20 

Burn,  forest  cover  established: 

Green  ink '. 

Yellow  ink ' 

Water...  8 


FOREST  ATLAS   CRAYONS. 


75 


Old  cuttings: 

Brick-red  ink 

Water 

Cultivated — red  ink. 
Mineral  lands — orange  ink. 
Open  for  cattle  and  horses  only: 

Brick-red  ink 

Water 

Open  for  sheep  and  goats  only: 

Yellow  ink 

Water 

Closed  for  all  stock — orange  ink. 
Driveways  for  stock: 

Black  ink 

Water... 


Parts. 
1 
3 


1 

20 


When  timber  or  woodland  has  been  partly  burned, 
the  lining  for  burns  may  be  used  on  top  of  tlie  green. 
When  partly  cut  over,  or  culled,  the  proper  signs  may 
be  used  in  the  same  manner. 


FOREST    ATLAS    CRAYONS. 


In  order  to  secure  uniformity  in  coloring  field  maps, 
boxes  containing  12  crayons  are  furnished,  with  a 
descriptive  label,  for  use  with  the  Forest  Atlas  legend. 
They  are  as  follows : 


v  COLORED   CRAYONS. 

General  classification. 


69.  Less  than  2,000  B.  F. 
29.  2,000  to  5,000  B.  F.  (light). 
29.  5,000  to  10,000  B.  F.  (heavy). 
15.  10,000  to  25,000  B.  F.  (light). 
15.  25,000 to 50,000  B.  F.  (heavy). 
63.  Woodland,  cordwood,  poles, 

etc. 

87.  Chaparral  or  brush. 
37.  Sagebrush. 


2.  Grassland,  parks. 
6609.  Barren,  above  timber  line, 

etc. 

63.  Burn,  forest  cover  estab- 
lished. 

72.  Old  cuttings. 
46.  Cultivated. 
62.  Mineral. 
58.  Water. 


76      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

Grazing  map  legend. 


58.  Administrative  divisions. 
72.  Open  for  cattle  and  horses 
only. 


2.  Open   for  sheep   and   goats 

only. 

62.  Closed  for  all  stock. 
87.  Driveways  for  stock. 


The  property  clerk  has  installed  a  machine  for  print- 
ing the  Forest  Atlas  legend  upon  each  colored  crayon, 
and  it  is  expected  that  this  improved  method  of  mark- 
ing will  lead  to  greater  accuracy  in  the  use  of  colors  on 
maps.  There  have  always  been  some  uncertainties, 
due  to  the  fact  that  many  men  are  not  good  judges  of 
color,  and  also  because  the  makers  of  colored  crayons 
change  the  formulae  for  mixing  colors  or  use  different 
grades  of  pigment.  It  has  also  been  found  in  the  case 
of  some  colors  that  they  change  materially  with  age. 
Under  this  new  method  of  marking  it  will  be  possible 
for  the  property  clerk  to  obtain  in  each  case  the  best 
grade  of  a  standard  color,  and,  disregarding  the  manu- 
facturer's number,  print  the  atlas  legend  upon  the 
pencil.  Thus,  the  bright  yellow  crayon  will  be  marked 
"Grassland,  parks,  etc.,"  and  "Open  for  sheep  and 
goats  only." 

On  important  work  a  legend  showing  the  colors  and 
symbols  used  and  their  significance  should  accompany 
each  map  or  folio. 

MOUNTING  MAPS  ON  MUSLIN. 

Slightly  dampen  the  muslin  and  stretch  it  over  a 
table  top  or  other  flat  surface.  Fasten  with  tacks  not 
more  than  4  inches  apart.  Wet  the  map  thoroughly  by 
dipping  it  in  water  or  with  a  sponge.  Remove  surplus 


MOUNTING  MAPS.  77 

water  with  large  blotters.  Lay  the  map  face  down 
upon  the  muslin,  and  with  a  wide  flat  brush  (rubber 
bound)  apply  paste  quickly  but  evenly  over  the  back  of 
the  map.  Turn  over  the  map  and  press  it  smoothly 
upon  the  muslin,  using  a  blotter  and  roller.  Leave  it 
to  dry  overnight.  The  hands  should  be  wet  when 
handling  a  wet  map  and  the  surface  of  the  map  should 
be  rubbed  as  little  as  possible.  It  is  better  for  two 
persons  to  work  together,  holding  all  four  corners  of  the 
map  and  allowing  it  to  fall  upon  the  muslin  from  the 
center  toward  the  corners,  thus  avoiding  air  bubbles. 
If  any  paste  gets  upon  the  face  of  the  map  it  should  be 
immediately  removed  with  a  wet  sponge. 

Three  or  four  layers  of  maps  may  be  mounted  on  the 
same  board,  provided  a  dry  piece  of  muslin  (same  size 
as  map)  be  placed  between  the  layers. 

In  some  instances,  for  convenience  in  folding  to 
pocket  or  other  small  size,  the  map  should  be  cut  into 
sections,  all  of  the  same  size  and  shape,  and  mounted 
with  a  slight  break  between  each  section,  where  the  fold 
will  come.  In  this  case,  each  small  sheet  must  be 
placed  separately  upon  the  big  sheet  of  muslin,  which 
has  been  previously  dampened  slightly. 

One  gallon  of  paste  may  be  made  as  follows :  Dissolve 
1^  pounds  of  lump  starch  in  1  gallon  of  water.  Then 
stir  constantly  while  pouring  boiling  water  over  it  until 
the  mixture  becomes  thick.  Set  aside,  and  when  almost 
cold  squeeze  through  a  piece  of  cheesecloth  in  order  to 
remove  the  lumps. 


78      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

METHOD   OF   USING  THE  FOREST   SERVICE   STANDARD 
PLANIMETER. 

Planimeters  are  issued  to  some  forest  officers  and  are 
used  to  determine  areas  platted  on  maps.  They  are 
constructed  to  register  areas  in  square  inches  and  deci- 


.  12. — Standard  planimeter. 

mals  of  1  square  inch  and  are  used  in  the  following 


manner: 


(1)  Place  the  weighted  stationary  pin,  A,  figure  12, 
outside  of  the  area  to  be  determined,  below  and  to  the 
left,  in  a  position  which  will  permit  the  "  tracing  pin/' 


STANDARD   PLANIMETER.  79 

B,  to  follow  the  entire  outline  freely.  If  the  area  to 
be  determined  is  too  large  to  permit  placing  the  sta- 
tionary pin  outside,  and  thus  determining  the  area  as 
a  whole,  the  area  may  be  divided  and  its  parts  deter- 
mined separately. 

(2)  Place  the  tracing  pin  at  any  starting  point  on  the 
outline  of  the  area  and  press  it  in  to  make  a  distinct 
mark  on  the  surface.     Set  all  the  scales  at  zero  with 
the  hand.     Then  draw  the  tracing  pin  around  the  out- 
line of  the  area,  following  it  as  exactly  as  possible,  until 
the  circuit  is  completed  and  the  tracing  pin  rests  at  the 
starting  point.     The  circuit  must  be  made  in  the  same 
direction  that  the  hands  of  a  watch  move. 

(3)  Four  figures,  representing  tens,  units,  tenths,  and 
hundredths,  may  be  read  after  the  circuit  is  completed, 
and  the  reading  may  be  from  00.01  to  99.99.     Figure 
12   shows   a  sample   reading   of   25.71    square  inches 
because  the  dial  C  registers  10  square  inches  for  each 
numbered  division.     The  roller  D  registers   1  square 
inch  for  each  numbered  division.     The  vernier  E  regis- 
ters 0.01  square  inch  to  be  read  against  D. 

It  will  be  noted  that  the  pointer  at  dial  C  points 
between  2  and  3.  The  area  in  square  inches  is,  there- 
fore, between  20  and  30.  The  zero  on  the  vernier  E 
serves  as  a  pointer  for  the  roller  D.  This  reads  be- 
tween 5  and  6.  Therefore  the  integral  area  is  25. 
Counting  the  divisions  between  the  figures  5  and  6,  it 
is  seen  that  the  zero  on  the  vernier  barely  passes  the 
seventh  mark.  Therefore  the  first  decimal  is  0.7.  By 
looking  along  the  vernier  E  it  will  be  seen  that  one  of 
the  graduations  falls  exactly  opposite  one  of  those  on 


80      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

roller  D.  This  will  happen  in  every  case  and  the  num- 
ber of  this  mark  on  the  vernier  will  determine  the 
second  decimal.  In  the  diagram  the  first  mark  to  the 
right  of  the  zero  falls  opposite  a  mark  on  roller  D  and 
therefore  the  reading  is  0.01.  Thus  the  total  reading 
is  25.71  square  inches.  Use  a  magnifying  glass  if 
necessary. 

(4)  The  area  in  acres  is  found  by  multiplying  the 
figure  given  by  the  planimeter  by  coefficient  determined 
by  the  scale  on  which  the  map  is  drawn.     If  the  scale 
be  1  inch  to  the  mile,  1  square  inch  will  represent  640 
acres.     If  it  be  one-half  inch  to  the  mile,  1  square  inch 
will  represent  4  square  miles  and  the  acreage  will  be 
determined  by  multiplying  the  instrument  reading  by 
640X4,  or  by  2,560.     If  the  scale  be  2  inches  to  the 
mile,  1  square  inch  will  represent  160  acres;  and  so  on 
for  any  desired  scale. 

(5)  Blueprints  and  other  photographic  papers  are 
never  exactly  to  scale,  but  a  conventional  mile  on  the 
print  can  be  planimetered,  and  the  reading  thus  ob- 
tained will  be  known  to  represent  640  acres. 

(6)  On  important  work  the  area  should  be  plani- 
metered several  times  and  the  results  averaged. 

(7)  For  practice,  a  regular  figure,  such  as  a  square 
containing  a  known  number  of  square  inches,  should 
be  planimetered  until  the  reading  on  the  instrument 
agrees  substantially  with  the  known  area. 

(8)  Only   an   expert   should    attempt   to    adjust   a 
planimeter.     If  the  instrument  does  not  work  properly 
it  should  be  returned  to  the  property  clerk  for  repairs. 


LAND   OFFICE    SURVEYS. 


LAND    OFFICE    SURVEYS. 


/ 
81 


The  rectangular  surveys  of  the  United  States  Land 
Office  control  throughout  the  West  and  divide  the  land 


FIG.  13.— Rectangular  system  of  Land  Office  surveys. 

surfaces  into  squares,  which  may  be  divided  and  sub- 
divided, quartered,  quarter-quartered,  etc.     The  unit- 

23682°— 12 6 


82      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

of  the  system  is  the  township,  wliich  is,  conventionally, 
6  miles  square  and  contains  36  sections  of  640  acres 
each,  or  23,040  acres. 

Inasmuch  as  meridian  lines  converge  toward  the 
North  Pole,  it  is  evident  that  townships  will  have  a 
trapezoidal  form  and  that  they  will  materially  decrease 
in  area  toward  the  north  unless  correction  lines  are 
introduced.  The  system  is  as  follows  (see  fig.  13,  p.  81) : 

Beginning  at  the  initial  points,  a  base  line  is  run  due 
east  and  west  with  standard  parallels  24  miles  distant. 
From  these  parallels  guide  meridians,  24  miles  distant, 
are  run  due  north  and  "close"  on  the  standard  paral- 
lels. This  divides  the  region  into  tracts  24  miles 
square,  except  for  the  convergence  mentioned.  Then 
township  lines  are  run,  making  tracts  which  are  6  miles 
square.  These  are  afterwards  " subdivided"  into  sec- 
tions. The  conventional  section  is  legally  subdivided 
into  quarters  and  quarter-quarters,  and  by  common 
usage  into  smaller  subdivisions,  but  unless  otherwise 
specified  these  are  all  proportionate  areas  to  the  quarter 
section.  A  conventional  section  is  cut  into  quarters  by 
straight  lines  which  connect  the  quarter  corners  on  its 
boundaries. 

Whenever,  as  in  the  case  of  timber  sales,  it  becomes 
necessary  to  survey  and  mark  a  line  which  bounds  some 
alienation,  it  is  important  that  the  line  should  be  either 
legally  correct  or  should  be  agreed  to  in  writing  by  the 
private  owner  for  the  purpose  of  the  sale,  and  in  case 
of  a  disagreement  no  timber  should  be  marked  for  cat- 
ting in  the  disputed  strip  until  the  merits  of  the  case 
have  been  submitted  to  the  Forester  and  his  instructions 
received. 


RESURVEYS MISLEADING    MARKS.  83 

There  are  many  exceptions  to  the  simple  rectangular 
scheme  as  outlined  above,  and  many  different  anoma- 
lous townships  and  sections  result  from  methods  which 
have  to  be  employed  in  special  cases. 

BE  SURVEYS. 

When  a  survey  is  to  be  made  in  a  township  which  has 
been  subdivided,  or  when  the  lines  of  old  survey  bound- 
aries are  to  be  retraced,  the  prime  object  is  to  follow  all 
of  the  legal  lines  and  to  check  up  on  all  of  the  legal  cor- 
ners. For  this  purpose  the  surveyor  should  know: 

(1)  The  date  when  the  original  survey  was  made. 

(2)  The  variation  used. 

(3)  The  change  in  variation,  increase  or  decrease, 
since  the  original  survey  was  made. 

In  any  Western  State  this  information  may  be  ob- 
tained from  the  surveyor  general,  and  usually  from  the 
county  surveyor  of  the  county  in  which  the  survey  is 
to  be  made.  In  any  event  the  new  variation,  as  deter- 
mined by  the  resurvey,  should  be  entered  in  the  field 
notes  for  future  reference. 

CANCELLATION    OF    MISLEADING    MARKS    ON 
FORMER   FOREST   BOUNDARY   POSTS. 

Forest  officers  are  cautioned  that  the  agreement  be- 
tween the  General  Land  Office  and  the  Forest  Service  in 
regard  to  the  cancellation  of  certain  misleading  markings 
on  National  Forest  boundary  posts  does  not  extend  to 
any  of  the  existing  regulations  against  changing 
markings  on  any  posts  other  than  as  herein  specified 


84      INSTRUCTIONS  FOR  MAKING  FOREST  SURVEYS,  ETC. 

Owing  to  changes  in  some  National  Forests  many  of 
the  metal  posts  used  to  mark  the  boundaries,  as  surveyed 
by  the  Geological  Survey  and  approved  by  the  General 
Land  Office,  have  become  misleading.  As  these  posts 
usually  mark  section  corners,  and  also  furnish  valuable 
points  for  reference,  they  must  not  be  removed,  but  their 
misleading  marks  may  be  canceled.  This  will  be  done 
by  cutting,  with  a  sharp  cold  chisel,  a  line  through  any 
misleading  word  or  words,  the  intention  being  to  cancel 
them  without  rendering  them  illegible. 

On  no  account  shall  any  portion  of  the  markings  which 
are  still  true,  or  partly  true,  be  thus  canceled.  For 
example,  in  the  following  cases,  the  words  which,  in  a 
National  Forest,  may  be  canceled  are  shown. 

AQUARIUS  FOREST  RESERVE  mWW  POST  NO.  27, 

BLACK  HILLS  BWWBAW  POST  NO.  18. 
UNITED  STATES  FOREST  RESERVE  SAK  JACIHTO  BOUNDARY  POST  NO.  43. 

Outside  of  a  National  Forest  the  words  which,  for 
example,  may  be  canceled  are  shown  thus: 

UNITED  STATES  FOREST  RESERVE  MADISON  30UKDARY  POST  NO.  37, 

In  every  case  when  any  mark  on  a  post  is  canceled 
the  same  cancellation  must  be  made  on  the  bearing  trees 
if  their  marks  are  misleading,  by  cutting  a  groove  across 
the  word. 

A  report  must  be  made  to  the  Forester  giving  the 
location  and  number  of  each  post  canceled  and  stating 
which  of  the  markings  thereon  have  been  canceled. 


PHYSIOGRAPHIC   FEATURES. 


85 


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